A170884 In the toothpick structure of A160160, the number of nodes occupied after n steps, assuming that the toothpicks have length 2.

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

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: A213215 A353578 A324719 * A182836 A360452 A097080

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