User blog comment:Deedlit11/Bignum Bakeoff appetizer/@comment-5529393-20140916042352

Here's the Goodstein function in Python:

i = 9 ** 9 ** 9 b = 2

def B(n): j = 0 while b**j <= n:		j += 1 j -= 1 return (b+1)**B(j) + B(n - b**j) if n else 0

while i:	i = B(i) - 1 b += 1 print b

104 characters.