Supplement txt files used as input data for problems.
Multiples of 3 and 5

233168
Moved completed problems into a separate folder.
Even Fibonacci numbers

4613732
Largest prime factor

6857
Largest palindrome product

906609
Smallest multiple

232792560
Sum square difference

25164150
10001st prime

104743
Largest product in a series

40824
Special Pythagorean triplet

31875000
Summation of primes

142913828922
Largest product in a grid

70600674
Highly divisible triangular number

76576500
Large sum

5537376230
Longest Collatz sequence

837799
Power digit sum

1366
Number letter counts

21124
Factorial digit sum

648
***** IN PROGRESS *****