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A183149 Number of toothpicks added at n-th stage to the toothpick structure of A183148. 2
0, 1, 3, 9, 9, 21, 9, 21, 21, 57, 9, 21, 21, 57, 21, 57, 57, 165, 9, 21, 21, 57, 21, 57, 57, 165, 21, 57, 57, 165, 57, 165, 165, 489, 9, 21, 21, 57, 21, 57, 57, 165, 21, 57, 57, 165, 57, 165, 165, 489, 21, 57, 57, 165, 57, 165 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

Essentially the first differences of A183148.

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

FORMULA

a(n) = 3*A183061(n-1), for n >=2

EXAMPLE

If written as a triangle begins:

0,

1,

3,

9,

9,21,

9,21,21,57,

9,21,21,57,21,57,57,165,

9,21,21,57,21,57,57,165,21,57,57,165,57,165,165,489,

CROSSREFS

Cf. A139250, A139251, A147582, A147610, A160173, A161411, A183061, A183127, A183148.

Sequence in context: A223195 A203600 A099720 * A223933 A224057 A224310

Adjacent sequences: A183146 A183147 A183148 * A183150 A183151 A183152

KEYWORD

nonn

AUTHOR

Omar E. Pol, Mar 28 2011, Apr 02 2011

STATUS

approved

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Last modified February 5 20:57 EST 2023. Contains 360087 sequences. (Running on oeis4.)