%I
%S 1,1,5,17,5,17,61,49,5,17,61,49,61,217,269,113,5,17,61,49,61,217,269,
%T 113,61,217,269,281,773,1241,877,241,5,17,61,49,61,217,269,113,61,217,
%U 269,281,773,1241,877,241,61,217,269,281,773,1241,877,409,773,1241,1381,2881,5269
%N a(0) = 1, a(1) = 1; a(2^i + j) = 2a(j) + 3a(j + 1) for 0 <= j < 2^i.
%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>
%K nonn
%O 0,3
%A _N. J. A. Sloane_, Jan 02 2010
