User blog comment:Deedlit11/Bignum Bakeoff appetizer/@comment-5529393-20140922175020

New algorithm for Goodstein.

i = 9 << 99999, b = 2;

B(x,y) { return y ? y % b * pow(b+1, B(0,x)) + B(x+1, y/b) : 0;}

main { while(b++, i = B(0,i)-1); return b;}

102 characters. Can anyone think of any possible improvements? I would love to get this to 100 characters or below!