OFFSET

1,3

COMMENTS

Number of Y-toothpicks added to the sieve at the n-th round.

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

FORMULA

a(n) = A161831(n+1)/2.

CROSSREFS

KEYWORD

more,nonn

AUTHOR

Omar E. Pol, Jun 20 2009

STATUS

approved