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 A170864 a(0) = 1, a(1) = 1; a(2^i + j) = 3a(j) + 2a(j + 1) for 0 <= j < 2^i. 1

%I #9 Feb 24 2021 02:48:19

%S 1,1,5,13,5,13,41,49,5,13,41,49,41,121,221,157,5,13,41,49,41,121,221,

%T 157,41,121,221,229,365,805,977,481,5,13,41,49,41,121,221,157,41,121,

%U 221,229,365,805,977,481,41,121,221,229,365,805,977,553,365,805,1121,1417,2705

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

%H Matthew House, <a href="/A170864/b170864.txt">Table of n, a(n) for n = 0..10000</a>

%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 0,3

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

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Last modified February 23 14:24 EST 2024. Contains 370283 sequences. (Running on oeis4.)