Hashlife

The 6,366,548,773,467,669,985,195,496,000 (6 octillionth) generation of a Turing machine in Life computed in less than 30 seconds on an Intel Core Duo 2GHz CPU using Hashlife in Golly. Computed by detecting a repeating cycle in the pattern, and skipping ahead to any requested generation.

Hashlife is a memoized algorithm for computing the long-term fate of a given starting configuration in Conway's Game of Life and related cellular automata, much more quickly than would be possible using alternative algorithms that simulate each time step of each cell of the automaton. The algorithm was first described by Bill Gosper in the early 1980s while he was engaged in research at the Xerox Palo Alto Research Center. Hashlife was originally implemented on Symbolics Lisp machines with the aid of the Flavors extension.