A160809 First differences of A160808.

1, 2, 4, 4, 4, 8, 12, 4, 1, 2, 3, 3, 4, 7, 8, 1, 2, 3, 3, 4, 5, 7, 5, 3, 5, 7, 8, 11, 13, 17, 12, 4, 5, 8, 7, 9, 5, 7, 9, 8, 4, 8, 8, 7, 8, 13, 14, 10, 8, 12, 11, 13, 13, 17, 16, 11, 8, 15, 13, 14, 19, 26, 21, 5, 7

Offset

1,2

Comments

Number of toothpicks added to the spiral at the n-th stage.

Links

Nathaniel Johnston, Table of n, a(n) for n = 1..254

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

Cf. A000045, A139250, A139251, A160426, A160427, A160800, A160801, A160802, A160803, A160808.

Sequence in context: A170893 A194445 A220525 * A139251 A342272 A182635

Adjacent sequences: A160806 A160807 A160808 * A160810 A160811 A160812

Keyword

nonn

Author

Omar E. Pol, May 26 2009

Extensions

Terms after a(16) from Nathaniel Johnston, Mar 30 2011

Status

approved