A151710 First differences of A160715.

1, 3, 3, 9, 3, 9, 9, 21, 3, 9, 9, 21, 15, 21, 27, 51, 3, 9, 9, 21, 15, 21, 27, 51, 21, 21, 27, 51

Offset

1,2

Comments

Number of Y-toothpick added at n-th stage to the structure of A160715.

Similar to A160121. [From Omar E. Pol, May 29 2010]

Links

Table of n, a(n) for n=1..28.

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

Example

Contribution from Omar E. Pol, Dec 18 2012 (Start):
Written as an irregular triangle begins:
1;
3;
3, 9;
3, 9, 9, 21;
3, 9, 9, 21, 15, 21, 27, 51;
3, 9, 9, 21, 15, 21, 27, 51, 21, 21, 27, 51,...
(End)

Crossrefs

Cf. A000225, A006516, A139250, A160120.

Cf. A048883, A139251, A151837, A160121.

Sequence in context: A165824 A256689 A266533 * A160121 A048883 A241717

Adjacent sequences: A151707 A151708 A151709 * A151711 A151712 A151713

Keyword

more,nonn

Author

Omar E. Pol, Jun 02 2009

Extensions

More terms from Omar E. Pol, May 29 2010

Status

approved