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A170884 In the toothpick structure of A160160, the number of nodes occupied after n steps, assuming that the toothpicks have length 2. 4
0, 3, 7, 15, 27, 39, 51, 67, 99, 155, 223, 263, 283, 299, 331, 387, 467, 555, 659, 811, 1067, 1443, 1831, 1995, 2059, 2083, 2123, 2179, 2259, 2347, 2451, 2603, 2859, 3235, 3659, 3955, 4211, 4483, 4899, 5451 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

See A170885 for the first differences.

LINKS

Table of n, a(n) for n=0..39.

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. A139250, A170885.

Sequence in context: A303220 A301894 A213215 * A182836 A097080 A274008

Adjacent sequences:  A170881 A170882 A170883 * A170885 A170886 A170887

KEYWORD

nonn

AUTHOR

David Applegate, Omar E. Pol and N. J. A. Sloane, Jan 09 2010

EXTENSIONS

a(7)-a(39) from Nathaniel Johnston, Nov 13 2010

STATUS

approved

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Last modified January 21 08:28 EST 2019. Contains 319351 sequences. (Running on oeis4.)