A183149 Number of toothpicks added at n-th stage to the toothpick structure of A183148.

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

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