A153007 Triangular number A000217(n) minus toothpick number A153006(n).

0, 0, 0, 0, 1, 2, 1, 0, 3, 8, 11, 13, 15, 13, 5, 0, 7, 20, 31, 41, 51, 57, 57, 59, 69, 79, 82, 81, 74, 51, 17, 0, 15, 44, 71, 97, 123, 145, 161, 179, 205, 231, 250, 265, 274, 267, 249, 247, 273, 307, 334, 357, 374, 375, 364, 363, 376, 380, 364, 332, 270, 163, 49, 0, 31, 92, 151

Offset: 0

Author

Omar E. Pol, Dec 19 2008, May 27 2009

Keywords

• nonn

Links

• 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 (A000217) and toothpick numbers (A153006) vs n [From _Omar E. Pol_, Apr 29 2009]

Crossrefs

Cf. A000217, A000225, A000396, A000668, A006516, A139250, A139251, A152980, A153006.

Formula

a(n) = A000217(n)-A153006(n).

Extensions

More terms from R. J. Mathar, Jul 13 2009