A161418 Number of triangles in the Y-toothpick structure after n rounds.

0, 0, 0, 0, 6, 6, 12, 12, 24, 30

Offset

0,5

Links

Table of n, a(n) for n=0..9.

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, A160120, A160124, A161419, A161828, A161836.

Sequence in context: A315784 A315785 A127402 * A124691 A315786 A112437

Adjacent sequences: A161415 A161416 A161417 * A161419 A161420 A161421

Keyword

more,nonn

Author

Omar E. Pol, Jun 21 2009

Status

approved