%I #16 Feb 04 2019 14:00:43

%S 1,3,6,6,6,18,18,18,6

%N a(n) is the number of elements added at n-th stage to the structure of the cellular automaton of A294980.

%H N. J. A. Sloane, <a href="/wiki/Catalog_of_Toothpick_and_CA_Sequences_in_OEIS">Catalog of Toothpick and Cellular Automata Sequences in the OEIS</a>

%H <a href="/index/Ce#cell">Index entries for sequences related to cellular automata</a>

%H <a href="/index/To#toothpick">Index entries for sequences related to toothpick sequences</a>

%e This cellular automaton has word "ab". The row lengths are the terms of A011782 multiplied by 2, so the structure of this irregular triangle is as follows:

%e a,b;

%e a,b;

%e a,b,a,b;

%e a,b,a,b,a,b,a,b;

%e a,b,a,b,a,b,a,b,a,b,a,b,a,b,a,b;

%e ...

%e Triangle begins:

%e 1, 3;

%e 6, 6;

%e 6, 18, 18, 18;

%e ...

%Y Cf. A294980, A296612 (gives more information about the "word" of a cellular automaton).

%Y Cf. A139251, A160121 (Y-toothpicks), A161207 (V-toothpicks).

%K nonn,tabf,more

%O 1,2

%A _Omar E. Pol_, Feb 10 2018