%I
%S 4,12,12,36,12,36,36,108,12,36,36,108,36,108,108,324,12,36,36,108,36,
%T 108,108,324,36,108,108,324,108,324,324,972,12,36,36,108,36,108,108,
%U 324,36,108,108,324,108,324,324,972,36,108,108,324,108,324,324,972,108,324,324
%N First differences of A160410.
%C The rows of the triangle in A147582 converge to this sequence.
%C Contribution from Omar E. Pol, Mar 28 2011 (Start):
%C a(n) is the number of cells turned "ON" at nth stage of the cellular automaton of A160410.
%C a(n) is also the number of toothpicks added at nth stage to the toothpick structure of A160410.
%C (End)
%H David Applegate, Omar E. Pol and N. J. A. Sloane, <a href="http://neilsloane.com/doc/tooth.pdf">The Toothpick Sequence and Other Sequences from Cellular Automata</a>, Congressus Numerantium, Vol. 206 (2010), 157191. [There is a typo in Theorem 6: (13) should read u(n) = 4.3^(wt(n1)1) for n >= 2.]
%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 Omar E. Pol, <a href="http://www.polprimos.com/imagenespub/polca024.jpg">Illustration of initial terms (Neighbors of the vertices)</a> [From _Omar E. Pol_, Nov 17 2009]
%F a(n) = A048883(n1)*4.
%e If written as a triangle:
%e .4;
%e .12;
%e .12,36;
%e .12,36,36,108;
%e .12,36,36,108,36,108,108,324;
%Y Cf. A139250, A139251, A160413, A160415, A160417.
%Y Cf. A000079, A048883, A147582, A160410, A160414.
%K nonn,tabf
%O 1,1
%A _Omar E. Pol_, May 20 2009, Jun 13 2009, Jun 14 2009
%E Edited by _David Applegate_ and _N. J. A. Sloane_, Jul 13 2009
