A256138 Total number of ON states after n generations of cellular automaton of A151723 based on hexagons, if we only look at two opposite 120-degree wedges, including the central cell.

1, 5, 9, 21, 25, 37, 57, 85, 89, 101, 121, 157, 193, 221, 273, 333, 337, 349, 369, 405, 441, 477, 545, 645, 713, 741, 793, 885, 993, 1069, 1193, 1317, 1321, 1333, 1353, 1389, 1425, 1461, 1529, 1629, 1697, 1733, 1801, 1917, 2065, 2197, 2361, 2589, 2721, 2749, 2801, 2893, 3001, 3109, 3281, 3549, 3785, 3893, 4017, 4237, 4513, 4709, 4985, 5237

Offset: 1

Author

Omar E. Pol, Mar 20 2015

Keywords

• nonn

Comments

First differs from both A169707 and A246335 at a(12).

First differs from the average of A169707 and A246335 at a(13).

Note that the above mentioned cellular automata work on the square grid.

A256139 gives the number of cells turned ON at the n-th stage.

Links

• N. J. A. Sloane, Catalog of Toothpick and Cellular Automata Sequences in the OEIS
• Index entries for sequences related to cellular automata

Crossrefs

Cf. A151723, A169707, A169779, A169780, A170898, A246333, A246335, A256139.

Formula

a(n) = 1 + 2*(A151723(n) - 1)/3 = 1 - 4*n + 4*A169780(n).

a(n) = 1 + 4*A169779(n-2), n >= 2.

a(n) = A151723(n) - 2*A169779(n-2), n >= 2.