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A170869 a(0) = 1, a(1) = 2; a(2^i + j) = 3a(j) + 2a(j + 1) for 0 <= j < 2^i. 0

%I #6 Feb 24 2021 02:48:19

%S 1,2,7,20,7,20,61,74,7,20,61,74,61,182,331,236,7,20,61,74,61,182,331,

%T 236,61,182,331,344,547,1208,1465,722,7,20,61,74,61,182,331,236,61,

%U 182,331,344,547,1208,1465,722,61,182,331,344,547,1208,1465,830,547,1208,1681,2126

%N a(0) = 1, a(1) = 2; a(2^i + j) = 3a(j) + 2a(j + 1) for 0 <= j < 2^i.

%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>

%K nonn

%O 0,2

%A _N. J. A. Sloane_, Jan 02 2010

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Last modified February 23 20:31 EST 2024. Contains 370288 sequences. (Running on oeis4.)