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A160809 First differences of A160808. 2
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 (list; graph; refs; listen; history; text; internal format)
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 A182635 A188346

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

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Last modified October 20 15:29 EDT 2019. Contains 328267 sequences. (Running on oeis4.)