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 A170850 G.f.: Prod_{k >= 0} (1 + 3x^(2^k-1) + 3x^(2^k)). 0

%I

%S 4,15,21,21,57,108,90,39,57,108,126,234,495,594,351,93,57,108,126,234,

%T 495,594,387,288,495,702,1080,2187,3267,2835,1296,255,57,108,126,234,

%U 495,594,387,288,495,702,1080,2187,3267,2835,1332,450,495,702,1080,2187,3267,2943

%N G.f.: Prod_{k >= 0} (1 + 3x^(2^k-1) + 3x^(2^k)).

%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), 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 0,1

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

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Last modified February 26 05:51 EST 2020. Contains 332277 sequences. (Running on oeis4.)