A122108 a(n)=number of 1's ("live" cells) at stage n of a 2-dimensional cellular automaton evolving by the rule: 1 if N+S+E+W is 1 or 2, else 0, starting from a single live cell.
1, 4, 8, 12, 20, 24, 44, 28, 52, 56, 104, 56, 104, 112, 212, 60, 116, 120, 232, 120, 232, 240, 464, 120, 232, 240, 464, 240, 464, 480, 932, 124, 244, 248, 488, 248, 488, 496, 976, 248, 488, 496, 976, 496, 976, 992, 1952, 248, 488, 496, 976, 496, 976, 992, 1952
Offset: 1
Keywords
Crossrefs
Cf. A048883.