A170872 - OEIS

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A170872

a(0) = 1, a(1) = 2; a(2^i + j) = 3a(j) + 3a(j + 1) for 0 <= j < 2^i.

2

1, 2, 9, 33, 9, 33, 126, 126, 9, 33, 126, 126, 126, 477, 756, 405, 9, 33, 126, 126, 126, 477, 756, 405, 126, 477, 756, 756, 1809, 3699, 3483, 1242, 9, 33, 126, 126, 126, 477, 756, 405, 126, 477, 756, 756, 1809, 3699, 3483, 1242, 126, 477, 756, 756, 1809, 3699, 3483, 1593

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,2

LINKS

Table of n, a(n) for n=0..55.

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: A264234 A056916 A139628 * A123142 A122097 A073400

Adjacent sequences: A170869 A170870 A170871 * A170873 A170874 A170875

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Jan 02 2010

STATUS

approved