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 A151665 G.f.: Product_{k>=0} (1 + 3*x^(4^k)). 18
 1, 3, 0, 0, 3, 9, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 9, 0, 0, 9, 27, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 9, 0, 0, 9, 27, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 9, 27, 0, 0, 27, 81, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS David Applegate, Omar E. Pol and N. J. A. Sloane, The Toothpick Sequence and Other Sequences from Cellular Automata, 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.] N. J. A. Sloane, Catalog of Toothpick and Cellular Automata Sequences in the OEIS CROSSREFS For generating functions Product_{k>=0} (1 + a*x^(b^k)) for the following values of (a,b) see: (1,2) A000012 and A000027, (1,3) A039966 and A005836, (1,4) A151666 and A000695, (1,5) A151667 and A033042, (2,2) A001316, (2,3) A151668, (2,4) A151669, (2,5) A151670, (3,2) A048883, (3,3) A117940, (3,4) A151665, (3,5) A151671, (4,2) A102376, (4,3) A151672, (4,4) A151673, (4,5) A151674. Sequence in context: A050452 A267875 A200517 * A171793 A079201 A079209 Adjacent sequences:  A151662 A151663 A151664 * A151666 A151667 A151668 KEYWORD nonn AUTHOR N. J. A. Sloane, May 30 2009 STATUS approved

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Last modified January 21 00:46 EST 2022. Contains 350473 sequences. (Running on oeis4.)