

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
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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), 157191. [There is a typo in Theorem 6: (13) should read u(n) = 4.3^(wt(n1)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: A301894 A213215 A324719 * 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



