A182842 a(n) = A182841(n+2)/2.

2, 4, 7, 8, 7, 12, 19, 16, 7, 12, 23, 32, 27, 28, 43, 32, 7, 12, 23, 32, 31, 40, 63, 72, 43, 28, 55, 84, 79, 72, 99, 64, 7, 12, 23, 32, 31, 40, 63, 72, 47, 40, 71, 112, 119, 112, 143, 152, 75, 28, 55, 84, 91, 108, 163, 204, 151, 88, 131, 204, 207, 180, 219, 128

Offset

0,1

Links

Olaf Voß, Table of n, a(n) for n = 0..998

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

Olaf Voß, Toothpick structures on hexagonal net

Index entries for sequences related to toothpick sequences

Example

From Omar E. Pol, Nov 01 2014: (Start)
When written as an irregular triangle with row lengths A011782:
2;
4;
7, 8;
7, 12, 19, 16;
7, 12, 23, 32, 27, 28, 43, 32;
7, 12, 23, 32, 31, 40, 63, 72, 43, 28, 55, 84, 79, 72, 99, 64;
7, 12, 23, 32, 31, 40, 63, 72, 47, 40, 71, 112, 119, 112, 143, 152, 75, 28, 55, 84, 91, 108, 163, 204, 151, 88, 131, 204, 207, 180, 219, 128;
The right border gives the even powers of 2, at least up a(2^9-1).
(End)

Crossrefs

Cf. A139250, A139251, A151724, A182633, A182840, A182841.

Sequence in context: A237199 A335192 A092577 * A009282 A141745 A301936

Adjacent sequences: A182839 A182840 A182841 * A182843 A182844 A182845

Keyword

nonn,tabf

Author

Omar E. Pol, Dec 11 2010

Extensions

More terms from Olaf Voß, Dec 24 2010

Wiki link added by Olaf Voß, Jan 14 2011

Status

approved