Euler problem #45

# Base on PE #44

def is_hexagonal_number(x):
    n = (math.sqrt(x * 8 + 1) + 1) / 4
    return int(n) if n.is_integer() else False


def cal_hexagonal_number(n):
    return n * (2 * n - 1)


def main():
    i = 143
    while True:
        i += 1
        r = cal_hexagonal_number(n)
        if is_pentagonal_number(r):
            return(i, r)


if __name__ == '__main__':
    main()


In [54]: %time main()
CPU times: user 19.3 ms, sys: 0 ns, total: 19.3 ms
Wall time: 19.2 ms
Out[54]: (27693, 1533776805)