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A170840
G.f.: Product_{k>=2} (1 + x^(2^k-1) + 3x^(2^k)).
0
1, 0, 0, 1, 3, 0, 0, 1, 3, 0, 1, 6, 9, 0, 0, 1, 3, 0, 1, 6, 9, 0, 1, 6, 9, 1, 9, 27, 27, 0, 0, 1, 3, 0, 1, 6, 9, 0, 1, 6, 9, 1, 9, 27, 27, 0, 1, 6, 9, 1, 9, 27, 27, 1, 9, 27, 28, 12, 54, 108, 81, 0, 0, 1, 3, 0, 1, 6, 9, 0, 1, 6, 9, 1, 9, 27, 27, 0, 1, 6, 9, 1, 9, 27, 27, 1, 9, 27, 28, 12, 54, 108, 81, 0
OFFSET
0,5
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.]
CROSSREFS
Sequence in context: A165974 A090622 A035696 * A300725 A035630 A126723
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Jan 02 2010
STATUS
approved