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A170865
a(0) = 1, a(1) = 1; a(2^i + j) = a(j) + 3a(j + 1) for 0 <= j < 2^i.
0
1, 1, 4, 13, 4, 13, 43, 25, 4, 13, 43, 25, 43, 142, 118, 37, 4, 13, 43, 25, 43, 142, 118, 37, 43, 142, 118, 154, 469, 496, 229, 49, 4, 13, 43, 25, 43, 142, 118, 37, 43, 142, 118, 154, 469, 496, 229, 49, 43, 142, 118, 154, 469, 496, 229, 166, 469, 496, 580, 1561, 1957, 1183
OFFSET
0,3
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: A212256 A265327 A130650 * A320030 A191509 A218356
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Jan 02 2010
STATUS
approved