WeixiangYan/CodeTransOcean huggingface dataset:
Task: Find largest left truncatable prime in a given base

C: #include <stdio.h>
#include <gmp.h>

typedef unsigned long ulong;

ulong small_primes[] = {2,3,5,7,11,13,17,19,23,29,31,37,41,
			43,47,53,59,61,67,71,73,79,83,89,97};

#define MAX_STACK 128
mpz_t tens[MAX_STACK], value[MAX_STACK], answer;

ulong base, seen_depth;

void add_digit(ulong i)
{
	ulong d;
	for (d = 1; d < base; d++) {
		mpz_set(value[i], value[i-1]);
		mpz_addmul_ui(value[i], tens[i], d);
		if (!mpz_probab_prime_p(value[i], 1)) continue;

		if (i > seen_depth ||
			(i == seen_depth && mpz_cmp(value[i], answer) == 1))
		{
			if (!mpz_probab_prime_p(value[i], 50)) continue;

			mpz_set(answer, value[i]);
			seen_depth = i;
			gmp_fprintf(stderr, "\tb=%lu d=%2lu | %Zd\n", base, i, answer);
		}

		add_digit(i+1);
	}
}

void do_base()
{
	ulong i;
	mpz_set_ui(answer, 0);
	mpz_set_ui(tens[0], 1);
	for (i = 1; i < MAX_STACK; i++)
		mpz_mul_ui(tens[i], tens[i-1], base);

	for (seen_depth = i = 0; small_primes[i] < base; i++) {
		fprintf(stderr, "\tb=%lu digit %lu\n", base, small_primes[i]);
		mpz_set_ui(value[0], small_primes[i]);
		add_digit(1);
	}
	gmp_printf("%d: %Zd\n", base, answer);
}

int main(void)
{
	ulong i;
	for (i = 0; i < MAX_STACK; i++) {
		mpz_init_set_ui(tens[i], 0);
		mpz_init_set_ui(value[i], 0);
	}
	mpz_init_set_ui(answer, 0);

	for (base = 22; base < 30; base++) do_base();

	return 0;
}



C#: using Mpir.NET;  
using System;   
using System.Collections.Generic;
class MaxLftTrP_B   
{
    static void Main()
    {
        mpz_t p; var sw = System.Diagnostics.Stopwatch.StartNew(); L(3);
        for (uint b = 3; b < 13; b++)
        {
            sw.Restart(); p = L(b);
            Console.WriteLine("{0} {1,2} {2}", sw.Elapsed, b, p);
        }
        Console.Read();
    }

    static mpz_t L(uint b)
    {
        var p = new List<mpz_t>(); mpz_t np = 0;
        while ((np = nxtP(np)) < b) p.Add(np);
        int i0 = 0, i = 0, i1 = p.Count - 1; mpz_t n0 = b, n, n1 = b * (b - 1);
        for (; i < p.Count; n0 *= b, n1 *= b, i0 = i1 + 1, i1 = p.Count - 1)
            for (n = n0; n <= n1; n += n0)
                for (i = i0; i <= i1; i++)
                    if (mpir.mpz_probab_prime_p(np = n + p[i], 15) > 0) p.Add(np);
        return p[p.Count - 1];
    }

    static mpz_t nxtP(mpz_t n) { mpz_t p = 0; mpir.mpz_nextprime(p, n); return p; }
}
Task: Find largest left truncatable prime in a given base

C: #include <stdio.h>
#include <gmp.h>

typedef unsigned long ulong;

ulong small_primes[] = {2,3,5,7,11,13,17,19,23,29,31,37,41,
			43,47,53,59,61,67,71,73,79,83,89,97};

#define MAX_STACK 128
mpz_t tens[MAX_STACK], value[MAX_STACK], answer;

ulong base, seen_depth;

void add_digit(ulong i)
{
	ulong d;
	for (d = 1; d < base; d++) {
		mpz_set(value[i], value[i-1]);
		mpz_addmul_ui(value[i], tens[i], d);
		if (!mpz_probab_prime_p(value[i], 1)) continue;

		if (i > seen_depth ||
			(i == seen_depth && mpz_cmp(value[i], answer) == 1))
		{
			if (!mpz_probab_prime_p(value[i], 50)) continue;

			mpz_set(answer, value[i]);
			seen_depth = i;
			gmp_fprintf(stderr, "\tb=%lu d=%2lu | %Zd\n", base, i, answer);
		}

		add_digit(i+1);
	}
}

void do_base()
{
	ulong i;
	mpz_set_ui(answer, 0);
	mpz_set_ui(tens[0], 1);
	for (i = 1; i < MAX_STACK; i++)
		mpz_mul_ui(tens[i], tens[i-1], base);

	for (seen_depth = i = 0; small_primes[i] < base; i++) {
		fprintf(stderr, "\tb=%lu digit %lu\n", base, small_primes[i]);
		mpz_set_ui(value[0], small_primes[i]);
		add_digit(1);
	}
	gmp_printf("%d: %Zd\n", base, answer);
}

int main(void)
{
	ulong i;
	for (i = 0; i < MAX_STACK; i++) {
		mpz_init_set_ui(tens[i], 0);
		mpz_init_set_ui(value[i], 0);
	}
	mpz_init_set_ui(answer, 0);

	for (base = 22; base < 30; base++) do_base();

	return 0;
}


C++: #include <gmpxx.h>

#include <algorithm>
#include <cassert>
#include <functional>
#include <iostream>
#include <vector>

using big_int = mpz_class;

const unsigned int small_primes[] = {2,  3,  5,  7,  11, 13, 17, 19, 23,
                                     29, 31, 37, 41, 43, 47, 53, 59, 61,
                                     67, 71, 73, 79, 83, 89, 97};

bool is_probably_prime(const big_int& n, int reps) {
    return mpz_probab_prime_p(n.get_mpz_t(), reps) != 0;
}

big_int largest_left_truncatable_prime(unsigned int base) {
    std::vector<big_int> powers = {1};
    std::vector<big_int> value = {0};
    big_int result = 0;

    std::function<void(unsigned int)> add_digit = [&](unsigned int i) {
        if (i == value.size()) {
            value.resize(i + 1);
            powers.push_back(base * powers.back());
        }
        for (unsigned int d = 1; d < base; ++d) {
            value[i] = value[i - 1] + powers[i] * d;
            if (!is_probably_prime(value[i], 1))
                continue;
            if (value[i] > result) {
                if (!is_probably_prime(value[i], 50))
                    continue;
                result = value[i];
            }
            add_digit(i + 1);
        }
    };

    for (unsigned int i = 0; small_primes[i] < base; ++i) {
        value[0] = small_primes[i];
        add_digit(1);
    }
    return result;
}

int main() {
    for (unsigned int base = 3; base < 18; ++base) {
        std::cout << base << ": " << largest_left_truncatable_prime(base)
                  << '\n';
    }
    for (unsigned int base = 19; base < 32; base += 2) {
        std::cout << base << ": " << largest_left_truncatable_prime(base)
                  << '\n';
    }
}
Task: Find largest left truncatable prime in a given base

C: #include <stdio.h>
#include <gmp.h>

typedef unsigned long ulong;

ulong small_primes[] = {2,3,5,7,11,13,17,19,23,29,31,37,41,
			43,47,53,59,61,67,71,73,79,83,89,97};

#define MAX_STACK 128
mpz_t tens[MAX_STACK], value[MAX_STACK], answer;

ulong base, seen_depth;

void add_digit(ulong i)
{
	ulong d;
	for (d = 1; d < base; d++) {
		mpz_set(value[i], value[i-1]);
		mpz_addmul_ui(value[i], tens[i], d);
		if (!mpz_probab_prime_p(value[i], 1)) continue;

		if (i > seen_depth ||
			(i == seen_depth && mpz_cmp(value[i], answer) == 1))
		{
			if (!mpz_probab_prime_p(value[i], 50)) continue;

			mpz_set(answer, value[i]);
			seen_depth = i;
			gmp_fprintf(stderr, "\tb=%lu d=%2lu | %Zd\n", base, i, answer);
		}

		add_digit(i+1);
	}
}

void do_base()
{
	ulong i;
	mpz_set_ui(answer, 0);
	mpz_set_ui(tens[0], 1);
	for (i = 1; i < MAX_STACK; i++)
		mpz_mul_ui(tens[i], tens[i-1], base);

	for (seen_depth = i = 0; small_primes[i] < base; i++) {
		fprintf(stderr, "\tb=%lu digit %lu\n", base, small_primes[i]);
		mpz_set_ui(value[0], small_primes[i]);
		add_digit(1);
	}
	gmp_printf("%d: %Zd\n", base, answer);
}

int main(void)
{
	ulong i;
	for (i = 0; i < MAX_STACK; i++) {
		mpz_init_set_ui(tens[i], 0);
		mpz_init_set_ui(value[i], 0);
	}
	mpz_init_set_ui(answer, 0);

	for (base = 22; base < 30; base++) do_base();

	return 0;
}







Python: import random

def is_probable_prime(n,k):
    
    if n==0 or n==1:
        return False
    if n==2:
        return True
    if n % 2 == 0:
        return False
    s = 0
    d = n-1

    while True:
        quotient, remainder = divmod(d, 2)
        if remainder == 1:
            break
        s += 1
        d = quotient

    def try_composite(a):
        if pow(a, d, n) == 1:
            return False
        for i in range(s):
            if pow(a, 2**i * d, n) == n-1:
                return False
        return True 
 
    for i in range(k):
        a = random.randrange(2, n)
        if try_composite(a):
            return False
 
    return True 
    
    
def largest_left_truncatable_prime(base):    
    radix = 0
    candidates = [0]
    while True:
        new_candidates=[]
        multiplier = base**radix
        for i in range(1,base):
            new_candidates += [x+i*multiplier for x in candidates if is_probable_prime(x+i*multiplier,30)]
        if len(new_candidates)==0:
            return max(candidates)
        candidates = new_candidates
        radix += 1

for b in range(3,24):
    print("%d:%d\n" % (b,largest_left_truncatable_prime(b)))
Task: Find largest left truncatable prime in a given base


C++: #include <gmpxx.h>

#include <algorithm>
#include <cassert>
#include <functional>
#include <iostream>
#include <vector>

using big_int = mpz_class;

const unsigned int small_primes[] = {2,  3,  5,  7,  11, 13, 17, 19, 23,
                                     29, 31, 37, 41, 43, 47, 53, 59, 61,
                                     67, 71, 73, 79, 83, 89, 97};

bool is_probably_prime(const big_int& n, int reps) {
    return mpz_probab_prime_p(n.get_mpz_t(), reps) != 0;
}

big_int largest_left_truncatable_prime(unsigned int base) {
    std::vector<big_int> powers = {1};
    std::vector<big_int> value = {0};
    big_int result = 0;

    std::function<void(unsigned int)> add_digit = [&](unsigned int i) {
        if (i == value.size()) {
            value.resize(i + 1);
            powers.push_back(base * powers.back());
        }
        for (unsigned int d = 1; d < base; ++d) {
            value[i] = value[i - 1] + powers[i] * d;
            if (!is_probably_prime(value[i], 1))
                continue;
            if (value[i] > result) {
                if (!is_probably_prime(value[i], 50))
                    continue;
                result = value[i];
            }
            add_digit(i + 1);
        }
    };

    for (unsigned int i = 0; small_primes[i] < base; ++i) {
        value[0] = small_primes[i];
        add_digit(1);
    }
    return result;
}

int main() {
    for (unsigned int base = 3; base < 18; ++base) {
        std::cout << base << ": " << largest_left_truncatable_prime(base)
                  << '\n';
    }
    for (unsigned int base = 19; base < 32; base += 2) {
        std::cout << base << ": " << largest_left_truncatable_prime(base)
                  << '\n';
    }
}


C#: using Mpir.NET;  
using System;   
using System.Collections.Generic;
class MaxLftTrP_B   
{
    static void Main()
    {
        mpz_t p; var sw = System.Diagnostics.Stopwatch.StartNew(); L(3);
        for (uint b = 3; b < 13; b++)
        {
            sw.Restart(); p = L(b);
            Console.WriteLine("{0} {1,2} {2}", sw.Elapsed, b, p);
        }
        Console.Read();
    }

    static mpz_t L(uint b)
    {
        var p = new List<mpz_t>(); mpz_t np = 0;
        while ((np = nxtP(np)) < b) p.Add(np);
        int i0 = 0, i = 0, i1 = p.Count - 1; mpz_t n0 = b, n, n1 = b * (b - 1);
        for (; i < p.Count; n0 *= b, n1 *= b, i0 = i1 + 1, i1 = p.Count - 1)
            for (n = n0; n <= n1; n += n0)
                for (i = i0; i <= i1; i++)
                    if (mpir.mpz_probab_prime_p(np = n + p[i], 15) > 0) p.Add(np);
        return p[p.Count - 1];
    }

    static mpz_t nxtP(mpz_t n) { mpz_t p = 0; mpir.mpz_nextprime(p, n); return p; }
}
Task: Find largest left truncatable prime in a given base


C++: #include <gmpxx.h>

#include <algorithm>
#include <cassert>
#include <functional>
#include <iostream>
#include <vector>

using big_int = mpz_class;

const unsigned int small_primes[] = {2,  3,  5,  7,  11, 13, 17, 19, 23,
                                     29, 31, 37, 41, 43, 47, 53, 59, 61,
                                     67, 71, 73, 79, 83, 89, 97};

bool is_probably_prime(const big_int& n, int reps) {
    return mpz_probab_prime_p(n.get_mpz_t(), reps) != 0;
}

big_int largest_left_truncatable_prime(unsigned int base) {
    std::vector<big_int> powers = {1};
    std::vector<big_int> value = {0};
    big_int result = 0;

    std::function<void(unsigned int)> add_digit = [&](unsigned int i) {
        if (i == value.size()) {
            value.resize(i + 1);
            powers.push_back(base * powers.back());
        }
        for (unsigned int d = 1; d < base; ++d) {
            value[i] = value[i - 1] + powers[i] * d;
            if (!is_probably_prime(value[i], 1))
                continue;
            if (value[i] > result) {
                if (!is_probably_prime(value[i], 50))
                    continue;
                result = value[i];
            }
            add_digit(i + 1);
        }
    };

    for (unsigned int i = 0; small_primes[i] < base; ++i) {
        value[0] = small_primes[i];
        add_digit(1);
    }
    return result;
}

int main() {
    for (unsigned int base = 3; base < 18; ++base) {
        std::cout << base << ": " << largest_left_truncatable_prime(base)
                  << '\n';
    }
    for (unsigned int base = 19; base < 32; base += 2) {
        std::cout << base << ": " << largest_left_truncatable_prime(base)
                  << '\n';
    }
}



Go: package main

import (
    "fmt"
    "math/big"
)

var smallPrimes = [...]int{2, 3, 5, 7, 11, 13, 17, 19, 23, 29}

const maxStack = 128

var (
    tens, values    [maxStack]big.Int
    bigTemp, answer = new(big.Int), new(big.Int)
    base, seenDepth int
)

func addDigit(i int) {
    for d := 1; d < base; d++ {
        values[i].Set(&values[i-1])
        bigTemp.SetUint64(uint64(d))
        bigTemp.Mul(bigTemp, &tens[i])
        values[i].Add(&values[i], bigTemp)
        if !values[i].ProbablyPrime(0) {
            continue
        }
        if i > seenDepth || (i == seenDepth && values[i].Cmp(answer) == 1) {
            if !values[i].ProbablyPrime(0) {
                continue
            }
            answer.Set(&values[i])
            seenDepth = i
        }
        addDigit(i + 1)
    }
}

func doBase() {
    answer.SetUint64(0)
    tens[0].SetUint64(1)
    bigTemp.SetUint64(uint64(base))
    seenDepth = 0
    for i := 1; i < maxStack; i++ {
        tens[i].Mul(&tens[i-1], bigTemp)
    }
    for i := 0; smallPrimes[i] < base; i++ {
        values[0].SetUint64(uint64(smallPrimes[i]))
        addDigit(1)
    }
    fmt.Printf("%2d: %s\n", base, answer.String())
}

func main() {
    for base = 3; base <= 17; base++ {
        doBase()
    }
}
Task: Find largest left truncatable prime in a given base


C++: #include <gmpxx.h>

#include <algorithm>
#include <cassert>
#include <functional>
#include <iostream>
#include <vector>

using big_int = mpz_class;

const unsigned int small_primes[] = {2,  3,  5,  7,  11, 13, 17, 19, 23,
                                     29, 31, 37, 41, 43, 47, 53, 59, 61,
                                     67, 71, 73, 79, 83, 89, 97};

bool is_probably_prime(const big_int& n, int reps) {
    return mpz_probab_prime_p(n.get_mpz_t(), reps) != 0;
}

big_int largest_left_truncatable_prime(unsigned int base) {
    std::vector<big_int> powers = {1};
    std::vector<big_int> value = {0};
    big_int result = 0;

    std::function<void(unsigned int)> add_digit = [&](unsigned int i) {
        if (i == value.size()) {
            value.resize(i + 1);
            powers.push_back(base * powers.back());
        }
        for (unsigned int d = 1; d < base; ++d) {
            value[i] = value[i - 1] + powers[i] * d;
            if (!is_probably_prime(value[i], 1))
                continue;
            if (value[i] > result) {
                if (!is_probably_prime(value[i], 50))
                    continue;
                result = value[i];
            }
            add_digit(i + 1);
        }
    };

    for (unsigned int i = 0; small_primes[i] < base; ++i) {
        value[0] = small_primes[i];
        add_digit(1);
    }
    return result;
}

int main() {
    for (unsigned int base = 3; base < 18; ++base) {
        std::cout << base << ": " << largest_left_truncatable_prime(base)
                  << '\n';
    }
    for (unsigned int base = 19; base < 32; base += 2) {
        std::cout << base << ": " << largest_left_truncatable_prime(base)
                  << '\n';
    }
}






Python: import random

def is_probable_prime(n,k):
    
    if n==0 or n==1:
        return False
    if n==2:
        return True
    if n % 2 == 0:
        return False
    s = 0
    d = n-1

    while True:
        quotient, remainder = divmod(d, 2)
        if remainder == 1:
            break
        s += 1
        d = quotient

    def try_composite(a):
        if pow(a, d, n) == 1:
            return False
        for i in range(s):
            if pow(a, 2**i * d, n) == n-1:
                return False
        return True 
 
    for i in range(k):
        a = random.randrange(2, n)
        if try_composite(a):
            return False
 
    return True 
    
    
def largest_left_truncatable_prime(base):    
    radix = 0
    candidates = [0]
    while True:
        new_candidates=[]
        multiplier = base**radix
        for i in range(1,base):
            new_candidates += [x+i*multiplier for x in candidates if is_probable_prime(x+i*multiplier,30)]
        if len(new_candidates)==0:
            return max(candidates)
        candidates = new_candidates
        radix += 1

for b in range(3,24):
    print("%d:%d\n" % (b,largest_left_truncatable_prime(b)))
Task: Find largest left truncatable prime in a given base



C#: using Mpir.NET;  
using System;   
using System.Collections.Generic;
class MaxLftTrP_B   
{
    static void Main()
    {
        mpz_t p; var sw = System.Diagnostics.Stopwatch.StartNew(); L(3);
        for (uint b = 3; b < 13; b++)
        {
            sw.Restart(); p = L(b);
            Console.WriteLine("{0} {1,2} {2}", sw.Elapsed, b, p);
        }
        Console.Read();
    }

    static mpz_t L(uint b)
    {
        var p = new List<mpz_t>(); mpz_t np = 0;
        while ((np = nxtP(np)) < b) p.Add(np);
        int i0 = 0, i = 0, i1 = p.Count - 1; mpz_t n0 = b, n, n1 = b * (b - 1);
        for (; i < p.Count; n0 *= b, n1 *= b, i0 = i1 + 1, i1 = p.Count - 1)
            for (n = n0; n <= n1; n += n0)
                for (i = i0; i <= i1; i++)
                    if (mpir.mpz_probab_prime_p(np = n + p[i], 15) > 0) p.Add(np);
        return p[p.Count - 1];
    }

    static mpz_t nxtP(mpz_t n) { mpz_t p = 0; mpir.mpz_nextprime(p, n); return p; }
}


Go: package main

import (
    "fmt"
    "math/big"
)

var smallPrimes = [...]int{2, 3, 5, 7, 11, 13, 17, 19, 23, 29}

const maxStack = 128

var (
    tens, values    [maxStack]big.Int
    bigTemp, answer = new(big.Int), new(big.Int)
    base, seenDepth int
)

func addDigit(i int) {
    for d := 1; d < base; d++ {
        values[i].Set(&values[i-1])
        bigTemp.SetUint64(uint64(d))
        bigTemp.Mul(bigTemp, &tens[i])
        values[i].Add(&values[i], bigTemp)
        if !values[i].ProbablyPrime(0) {
            continue
        }
        if i > seenDepth || (i == seenDepth && values[i].Cmp(answer) == 1) {
            if !values[i].ProbablyPrime(0) {
                continue
            }
            answer.Set(&values[i])
            seenDepth = i
        }
        addDigit(i + 1)
    }
}

func doBase() {
    answer.SetUint64(0)
    tens[0].SetUint64(1)
    bigTemp.SetUint64(uint64(base))
    seenDepth = 0
    for i := 1; i < maxStack; i++ {
        tens[i].Mul(&tens[i-1], bigTemp)
    }
    for i := 0; smallPrimes[i] < base; i++ {
        values[0].SetUint64(uint64(smallPrimes[i]))
        addDigit(1)
    }
    fmt.Printf("%2d: %s\n", base, answer.String())
}

func main() {
    for base = 3; base <= 17; base++ {
        doBase()
    }
}
Task: Find largest left truncatable prime in a given base




Go: package main

import (
    "fmt"
    "math/big"
)

var smallPrimes = [...]int{2, 3, 5, 7, 11, 13, 17, 19, 23, 29}

const maxStack = 128

var (
    tens, values    [maxStack]big.Int
    bigTemp, answer = new(big.Int), new(big.Int)
    base, seenDepth int
)

func addDigit(i int) {
    for d := 1; d < base; d++ {
        values[i].Set(&values[i-1])
        bigTemp.SetUint64(uint64(d))
        bigTemp.Mul(bigTemp, &tens[i])
        values[i].Add(&values[i], bigTemp)
        if !values[i].ProbablyPrime(0) {
            continue
        }
        if i > seenDepth || (i == seenDepth && values[i].Cmp(answer) == 1) {
            if !values[i].ProbablyPrime(0) {
                continue
            }
            answer.Set(&values[i])
            seenDepth = i
        }
        addDigit(i + 1)
    }
}

func doBase() {
    answer.SetUint64(0)
    tens[0].SetUint64(1)
    bigTemp.SetUint64(uint64(base))
    seenDepth = 0
    for i := 1; i < maxStack; i++ {
        tens[i].Mul(&tens[i-1], bigTemp)
    }
    for i := 0; smallPrimes[i] < base; i++ {
        values[0].SetUint64(uint64(smallPrimes[i]))
        addDigit(1)
    }
    fmt.Printf("%2d: %s\n", base, answer.String())
}

func main() {
    for base = 3; base <= 17; base++ {
        doBase()
    }
}




Python: import random

def is_probable_prime(n,k):
    
    if n==0 or n==1:
        return False
    if n==2:
        return True
    if n % 2 == 0:
        return False
    s = 0
    d = n-1

    while True:
        quotient, remainder = divmod(d, 2)
        if remainder == 1:
            break
        s += 1
        d = quotient

    def try_composite(a):
        if pow(a, d, n) == 1:
            return False
        for i in range(s):
            if pow(a, 2**i * d, n) == n-1:
                return False
        return True 
 
    for i in range(k):
        a = random.randrange(2, n)
        if try_composite(a):
            return False
 
    return True 
    
    
def largest_left_truncatable_prime(base):    
    radix = 0
    candidates = [0]
    while True:
        new_candidates=[]
        multiplier = base**radix
        for i in range(1,base):
            new_candidates += [x+i*multiplier for x in candidates if is_probable_prime(x+i*multiplier,30)]
        if len(new_candidates)==0:
            return max(candidates)
        candidates = new_candidates
        radix += 1

for b in range(3,24):
    print("%d:%d\n" % (b,largest_left_truncatable_prime(b)))
Task: Find largest left truncatable prime in a given base

C: #include <stdio.h>
#include <gmp.h>

typedef unsigned long ulong;

ulong small_primes[] = {2,3,5,7,11,13,17,19,23,29,31,37,41,
			43,47,53,59,61,67,71,73,79,83,89,97};

#define MAX_STACK 128
mpz_t tens[MAX_STACK], value[MAX_STACK], answer;

ulong base, seen_depth;

void add_digit(ulong i)
{
	ulong d;
	for (d = 1; d < base; d++) {
		mpz_set(value[i], value[i-1]);
		mpz_addmul_ui(value[i], tens[i], d);
		if (!mpz_probab_prime_p(value[i], 1)) continue;

		if (i > seen_depth ||
			(i == seen_depth && mpz_cmp(value[i], answer) == 1))
		{
			if (!mpz_probab_prime_p(value[i], 50)) continue;

			mpz_set(answer, value[i]);
			seen_depth = i;
			gmp_fprintf(stderr, "\tb=%lu d=%2lu | %Zd\n", base, i, answer);
		}

		add_digit(i+1);
	}
}

void do_base()
{
	ulong i;
	mpz_set_ui(answer, 0);
	mpz_set_ui(tens[0], 1);
	for (i = 1; i < MAX_STACK; i++)
		mpz_mul_ui(tens[i], tens[i-1], base);

	for (seen_depth = i = 0; small_primes[i] < base; i++) {
		fprintf(stderr, "\tb=%lu digit %lu\n", base, small_primes[i]);
		mpz_set_ui(value[0], small_primes[i]);
		add_digit(1);
	}
	gmp_printf("%d: %Zd\n", base, answer);
}

int main(void)
{
	ulong i;
	for (i = 0; i < MAX_STACK; i++) {
		mpz_init_set_ui(tens[i], 0);
		mpz_init_set_ui(value[i], 0);
	}
	mpz_init_set_ui(answer, 0);

	for (base = 22; base < 30; base++) do_base();

	return 0;
}




Go: package main

import (
    "fmt"
    "math/big"
)

var smallPrimes = [...]int{2, 3, 5, 7, 11, 13, 17, 19, 23, 29}

const maxStack = 128

var (
    tens, values    [maxStack]big.Int
    bigTemp, answer = new(big.Int), new(big.Int)
    base, seenDepth int
)

func addDigit(i int) {
    for d := 1; d < base; d++ {
        values[i].Set(&values[i-1])
        bigTemp.SetUint64(uint64(d))
        bigTemp.Mul(bigTemp, &tens[i])
        values[i].Add(&values[i], bigTemp)
        if !values[i].ProbablyPrime(0) {
            continue
        }
        if i > seenDepth || (i == seenDepth && values[i].Cmp(answer) == 1) {
            if !values[i].ProbablyPrime(0) {
                continue
            }
            answer.Set(&values[i])
            seenDepth = i
        }
        addDigit(i + 1)
    }
}

func doBase() {
    answer.SetUint64(0)
    tens[0].SetUint64(1)
    bigTemp.SetUint64(uint64(base))
    seenDepth = 0
    for i := 1; i < maxStack; i++ {
        tens[i].Mul(&tens[i-1], bigTemp)
    }
    for i := 0; smallPrimes[i] < base; i++ {
        values[0].SetUint64(uint64(smallPrimes[i]))
        addDigit(1)
    }
    fmt.Printf("%2d: %s\n", base, answer.String())
}

func main() {
    for base = 3; base <= 17; base++ {
        doBase()
    }
}