Buggy python submission (verdict: Time Limit Exceeded):
n = int(input())
s = str(input())

check = dict()
def get_pattern2(i, j):
    a = s[i]
    b = s[j]
    total = 0
    check_str = ""
    if a == "R" or b == "R":
        check_str += "R"
    if a == "G" or b == "G":
        check_str += "G"
    if a == "B" or b == "B":
        check_str += "B"

    for k in range(j+1, n):
        if check_str+str(k) in check:
            total += check[check_str+str(k)]
            break
        if a != s[k] and b != s[k]:
            total += 1
    check[check_str+str(j+1)] = total
    return total

def get_pattern(i):
    a = s[i]
    total = 0
    for j in range(i+1, n):
        if a+str(j) in check:
            total += check[a+str(j)]
            break
        if a != s[j]:
            total += get_pattern2(i, j)
    check[a+str(i+1)] = total

    # k-j = i-jなものをぬく
    for j in range(i+1, n):
        k = j + j - i
        if k >= n:
            break
        if a != s[k] and s[j] != s[k] and a != s[j]:
            total -= 1

    return total

total = 0
for i in range(n-1, -1, -1):
    total += get_pattern(i)
print(total)


Fixed submission:
n = int(input())
s = str(input())

check = dict()
def get_pattern2(i, j):
    a = s[i]
    b = s[j]
    total = 0
    check_str = ""
    if a == "R" or b == "R":
        check_str += "R"
    if a == "G" or b == "G":
        check_str += "G"
    if a == "B" or b == "B":
        check_str += "B"

    for k in range(j+1, n):
        if check_str+str(k) in check:
            total += check[check_str+str(k)]
            break
        if a != s[k] and b != s[k]:
            total += 1
    check[check_str+str(j+1)] = total
    return total

def get_pattern(i):
    a = s[i]
    total = 0
    for j in range(i+1, n):
        if a+str(j) in check:
            total += check[a+str(j)]
            break
        if a != s[j]:
            total += get_pattern2(i, j)
    check[a+str(i+1)] = total

    # k-j = i-jなものをぬく
    for j in range(i+1, n):
        k = j + j - i
        if k >= n:
            break
        if a != s[k] and s[j] != s[k] and a != s[j]:
            total -= 1
    return total

total = 0
for i in range(n-1, -1, -1):
    total += get_pattern(i)
print(total)

Buggy python submission (verdict: Time Limit Exceeded):
n = int(input())
s = str(input())

check = dict()
def get_pattern2(i, j):
    a = s[i]
    b = s[j]
    total = 0
    check_str = ""
    if a == "R" or b == "R":
        check_str += "R"
    if a == "G" or b == "G":
        check_str += "G"
    if a == "B" or b == "B":
        check_str += "B"

    for k in range(j+1, n):
        if check_str+str(k) in check:
            total += check[check_str+str(k)]
            break
        if a != s[k] and b != s[k]:
            total += 1
    check[check_str+str(j+1)] = total
    return total

def get_pattern(i):
    a = s[i]
    total = 0
    for j in range(i+1, n):
        if a+str(j) in check:
            total += check[a+str(j)]
            break
        if a != s[j]:
            total += get_pattern2(i, j)
    check[a+str(i+1)] = total

    # k-j = i-jなものをぬく
    for j in range(i+1, n):
        k = j + j - i
        if k < n:
            if a != s[k] and s[j] != s[k] and a != s[j]:
                total -= 1

    return total

total = 0
for i in range(n-1, -1, -1):
    total += get_pattern(i)
print(total)


Fixed submission:
n = int(input())
s = str(input())

check = dict()
def get_pattern2(i, j):
    a = s[i]
    b = s[j]
    total = 0
    check_str = ""
    if a == "R" or b == "R":
        check_str += "R"
    if a == "G" or b == "G":
        check_str += "G"
    if a == "B" or b == "B":
        check_str += "B"

    for k in range(j+1, n):
        if check_str+str(k) in check:
            total += check[check_str+str(k)]
            break
        if a != s[k] and b != s[k]:
            total += 1
    check[check_str+str(j+1)] = total
    return total

def get_pattern(i):
    a = s[i]
    total = 0
    for j in range(i+1, n):
        if a+str(j) in check:
            total += check[a+str(j)]
            break
        if a != s[j]:
            total += get_pattern2(i, j)
    check[a+str(i+1)] = total

    # k-j = i-jなものをぬく
    for j in range(i+1, n):
        k = j + j - i
        if k >= n:
            break
        if a != s[k] and s[j] != s[k] and a != s[j]:
            total -= 1
    return total

total = 0
for i in range(n-1, -1, -1):
    total += get_pattern(i)
print(total)

Buggy python submission (verdict: Time Limit Exceeded):
n = int(input())
s = str(input())

check = dict()
def get_pattern2(i, j):
    a = s[i]
    b = s[j]
    total = 0
    check_str = ""
    if a == "R" or b == "R":
        check_str += "R"
    if a == "G" or b == "G":
        check_str += "G"
    if a == "B" or b == "B":
        check_str += "B"

    for k in range(j+1, n):
        if check_str+str(k) in check:
            total += check[check_str+str(k)]
            break
        if a != s[k] and b != s[k]:
            total += 1
    check[check_str+str(j+1)] = total
    return total

def get_pattern(i):
    a = s[i]
    total = 0
    for j in range(i+1, n):
        if a+str(i) in check:
            total += check[a+str(i)]
            break
        if a != s[j]:
            total += get_pattern2(i, j)
    check[a+str(i)] = total

    # k-j = i-jなものをぬく
    for j in range(i+1, n):
        k = j + j - i
        if k < n:
            if a != s[k] and s[j] != s[k] and a != s[j]:
                total -= 1

    return total

total = 0
for i in range(n-1, -1, -1):
    total += get_pattern(i)
print(total)


Fixed submission:
n = int(input())
s = str(input())

check = dict()
def get_pattern2(i, j):
    a = s[i]
    b = s[j]
    total = 0
    check_str = ""
    if a == "R" or b == "R":
        check_str += "R"
    if a == "G" or b == "G":
        check_str += "G"
    if a == "B" or b == "B":
        check_str += "B"

    for k in range(j+1, n):
        if check_str+str(k) in check:
            total += check[check_str+str(k)]
            break
        if a != s[k] and b != s[k]:
            total += 1
    check[check_str+str(j+1)] = total
    return total

def get_pattern(i):
    a = s[i]
    total = 0
    for j in range(i+1, n):
        if a+str(j) in check:
            total += check[a+str(j)]
            break
        if a != s[j]:
            total += get_pattern2(i, j)
    check[a+str(i+1)] = total

    # k-j = i-jなものをぬく
    for j in range(i+1, n):
        k = j + j - i
        if k >= n:
            break
        if a != s[k] and s[j] != s[k] and a != s[j]:
            total -= 1
    return total

total = 0
for i in range(n-1, -1, -1):
    total += get_pattern(i)
print(total)

Buggy python submission (verdict: Time Limit Exceeded):
n = int(input())
s = str(input())

check = dict()
def get_pattern2(i, j):
    a = s[i]
    b = s[j]
    total = 0
    check_str = ""
    if a == "R" or b == "R":
        check_str += "R"
    if a == "G" or b == "G":
        check_str += "G"
    if a == "B" or b == "B":
        check_str += "B"

    center = j - i
    if n < j + 1 + center:
        center = 0

    for k in range(j+1+center, n):
        if check_str+str(k) in check:
            total += check[check_str+str(k)]
            break
        if a != s[k] and b != s[k]:
            total += 1
    check[check_str+str(j+1+center)] = total

    for k in range(j+1, j+center):
        if a != s[k] and b != s[k]:
            total += 1
    return total

def get_pattern(i):
    a = s[i]
    total = 0
    for j in range(i+1, n):
        center = j - i
        if n < j + 1 + center:
            if a+str(i) in check:
                total += check[a+str(i)]
                break
        if a != s[j]:
            total += get_pattern2(i, j)
    check[a+str(i)] = total
    return total

total = 0
for i in range(n-1, -1, -1):
    total += get_pattern(i)
print(total)


Fixed submission:
n = int(input())
s = str(input())

check = dict()
def get_pattern2(i, j):
    a = s[i]
    b = s[j]
    total = 0
    check_str = ""
    if a == "R" or b == "R":
        check_str += "R"
    if a == "G" or b == "G":
        check_str += "G"
    if a == "B" or b == "B":
        check_str += "B"

    for k in range(j+1, n):
        if check_str+str(k) in check:
            total += check[check_str+str(k)]
            break
        if a != s[k] and b != s[k]:
            total += 1
    check[check_str+str(j+1)] = total
    return total

def get_pattern(i):
    a = s[i]
    total = 0
    for j in range(i+1, n):
        if a+str(j) in check:
            total += check[a+str(j)]
            break
        if a != s[j]:
            total += get_pattern2(i, j)
    check[a+str(i+1)] = total

    # k-j = i-jなものをぬく
    for j in range(i+1, n):
        k = j + j - i
        if k >= n:
            break
        if a != s[k] and s[j] != s[k] and a != s[j]:
            total -= 1
    return total

total = 0
for i in range(n-1, -1, -1):
    total += get_pattern(i)
print(total)

Buggy python submission (verdict: Time Limit Exceeded):
n = int(input())
s = str(input())

check = dict()
def get_pattern2(i, j):
    a = s[i]
    b = s[j]
    total = 0
    check_str = ""
    if a == "R" or b == "R":
        check_str += "R"
    if a == "G" or b == "G":
        check_str += "G"
    if a == "B" or b == "B":
        check_str += "B"

    center = j - i
    if n < j + 1 + center:
        center = 0

    for k in range(j+1+center, n):
        if check_str+str(k) in check:
            total += check[check_str+str(k)]
            break
        if a != s[k] and b != s[k]:
            total += 1
    check[check_str+str(j+1+center)] = total

    for k in range(j+1, j+center):
        if a != s[k] and b != s[k]:
            total += 1
    return total

def get_pattern(i):
    a = s[i]
    total = 0
    for j in range(i+1, n):
        if a != s[j]:
            total += get_pattern2(i, j)
    return total

total = 0
for i in range(n-1, -1, -1):
    total += get_pattern(i)
print(total)


Fixed submission:
n = int(input())
s = str(input())

check = dict()
def get_pattern2(i, j):
    a = s[i]
    b = s[j]
    total = 0
    check_str = ""
    if a == "R" or b == "R":
        check_str += "R"
    if a == "G" or b == "G":
        check_str += "G"
    if a == "B" or b == "B":
        check_str += "B"

    for k in range(j+1, n):
        if check_str+str(k) in check:
            total += check[check_str+str(k)]
            break
        if a != s[k] and b != s[k]:
            total += 1
    check[check_str+str(j+1)] = total
    return total

def get_pattern(i):
    a = s[i]
    total = 0
    for j in range(i+1, n):
        if a+str(j) in check:
            total += check[a+str(j)]
            break
        if a != s[j]:
            total += get_pattern2(i, j)
    check[a+str(i+1)] = total

    # k-j = i-jなものをぬく
    for j in range(i+1, n):
        k = j + j - i
        if k >= n:
            break
        if a != s[k] and s[j] != s[k] and a != s[j]:
            total -= 1
    return total

total = 0
for i in range(n-1, -1, -1):
    total += get_pattern(i)
print(total)