Rule
54 is one of the
elementary cellular automaton rules introduced by Stephen Wolfram in 1983 (Wolfram 1983, 2002). It specifies the next color in a cell, depending on its color and its immediate neighbors. Its rule outcomes are encoded in the
binary representation
http://mathworld.wolfram.com/images/...54/Inline1.gif.
Starting with a single black cell, successive generations
http://mathworld.wolfram.com/images/...54/Inline2.gif, 1, ... are given by interpreting the numbers 1, 7, 17, 119, 273, 1911, 4369, 30583, ... (Sloane's
A118108) in binary, namely 1, 111, 10001, 1110111, 100010001, ... (Sloane's
A118109). The decimal value of the
http://mathworld.wolfram.com/images/...54/Inline3.gifth iteration is given in closed form by