A246311 Number of ON cells at generation n of 2-D cellular automaton in which a cell is ON iff either 1 or 2 of its eight neighbors were ON at previous generation, starting with a single ON cell.

1, 8, 16, 24, 28, 56, 68, 88, 112, 116, 148, 216, 232, 260, 400, 320, 420, 440, 508, 472, 512, 564, 752, 684, 876, 896, 1064, 1064, 1224, 1368, 1620, 1396, 1564, 1612, 1756, 1632, 1976, 1676, 2008, 1848, 2016, 2080, 2332, 2004, 2488, 2332, 2988, 2516, 2868, 3008, 3184, 2956, 3476, 3432, 3556, 3532, 4008, 4116, 4676, 4308, 4984, 5044, 6044, 5148, 5780, 5780, 6200

Offset

0,2

Comments

This is the Rule 60 outer totalistic 8-neighbor 2-D CA.

The first few generations are easy to understand, but then there are complications (hence the keyword "look", which refers to the illustrations).

Links

Table of n, a(n) for n=0..66.

N. J. A. Sloane, Illustration of first 28 generations

Mathematica

Total@*Total /@ CellularAutomaton[{60, {2, {{2, 2, 2}, {2, 1, 2}, {2, 2, 2}}}, {1, 1}}, {{{1}}, 0}, 66]
ArrayPlot /@ CellularAutomaton[{60, {2, {{2, 2, 2}, {2, 1, 2}, {2, 2, 2}}}, {1, 1}}, {{{1}}, 0}, 28]

Crossrefs

Sequence in context: A033859 A177899 A358727 * A344538 A244371 A144566

Adjacent sequences: A246308 A246309 A246310 * A246312 A246313 A246314

Keyword

nonn,look

Author

N. J. A. Sloane, Aug 23 2014

Status

approved