%I #9 Feb 24 2021 02:48:19
%S 1,2,3,4,6,7,7,9,9,10,12,12,19,17,21,17,13,14,16,19,25,27,29,29,33,30,
%T 28,25,33,33,33,35,21,26,28,27,31,33,39,44
%N a(n) = A172311(n+1)/2.
%H David Applegate, Omar E. Pol and N. J. A. Sloane, <a href="/A000695/a000695_1.pdf">The Toothpick Sequence and Other Sequences from Cellular Automata</a>, Congressus Numerantium, Vol. 206 (2010), 157-191. [There is a typo in Theorem 6: (13) should read u(n) = 4.3^(wt(n-1)-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>
%Y Cf. A139250, A139251, A172310, A172311.
%K nonn
%O 1,2
%A _Omar E. Pol_, Jan 31 2010
%E More terms from _Nathaniel Johnston_, Nov 15 2010