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 A170867 a(0) = 1, a(1) = 1; a(2^i + j) = 3a(j) + 3a(j + 1) for 0 <= j < 2^i. 0
 1, 1, 6, 21, 6, 21, 81, 81, 6, 21, 81, 81, 81, 306, 486, 261, 6, 21, 81, 81, 81, 306, 486, 261, 81, 306, 486, 486, 1161, 2376, 2241, 801, 6, 21, 81, 81, 81, 306, 486, 261, 81, 306, 486, 486, 1161, 2376, 2241, 801, 81, 306, 486, 486, 1161, 2376, 2241, 1026, 1161, 2376, 2916 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS Table of n, a(n) for n=0..58. 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 Sequence in context: A338427 A069257 A133885 * A321776 A064929 A298266 Adjacent sequences: A170864 A170865 A170866 * A170868 A170869 A170870 KEYWORD nonn AUTHOR N. J. A. Sloane, Jan 02 2010 STATUS approved

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Last modified November 30 23:40 EST 2023. Contains 367464 sequences. (Running on oeis4.)