A159790 Toothpick number A139250(n) minus triangular number A000217(n).

0, 0, 0, 1, 1, 0, 2, 7, 7, 2, 0, 1, 1, 4, 18, 35, 35, 22, 12, 5, -3, -8, -2, 7, 3, -6, -4, 5, 17, 48, 106, 155, 155, 126, 100, 77, 53, 32, 22, 15, -5, -30, -44, -51, -55, -40, 2, 35, 23, -10, -32, -47, -59, -52, -18, 11, 11, 14, 48, 101, 181, 328, 522, 651, 651, 590, 532

Offset

0,7

Links

Table of n, a(n) for n=0..66.

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

OEIS Plot 2, Triangular numbers and toothpick numbers vs n

Crossrefs

Sequence in context: A011052 A329208 A153738 * A251809 A016639 A138341

Adjacent sequences: A159787 A159788 A159789 * A159791 A159792 A159793

Keyword

sign

Author

Omar E. Pol, May 03 2009

Extensions

More terms from R. J. Mathar, May 04 2009

Status

approved