A338097 Number of ON cells after n generations of cellular automaton based on a hexagonal grid and starting with two adjacent ON cells where an OFF cell is turned ON if exactly two of its six neighbors are ON.

0, 2, 4, 8, 12, 18, 22, 28, 32, 36, 44, 56, 76, 86, 100, 116, 130, 144, 164, 178, 198, 218, 242, 260, 282, 306, 350, 386, 414, 446, 460, 484, 516, 556, 586, 638, 688, 736, 770, 800, 828, 872, 914, 964, 1012, 1068, 1122, 1162, 1204, 1252, 1300, 1360, 1408, 1462

Offset: 0

Author

Rémy Sigrist, Oct 10 2020

Keywords

• nonn

Comments

An ON cell remains ON forever.

Links

• Rémy Sigrist, Table of n, a(n) for n = 0..8192
• Rémy Sigrist, Illustration of initial terms
• Rémy Sigrist, Illustration of the structure at generation 512
• Rémy Sigrist, PARI program for A338097
• Index entries for sequences related to cellular automata

Crossrefs

Cf. A151731 (square grid variant), A338098.

Programs

PARI

See Links section.