OFFSET

0,2

COMMENTS

This sequence (for Ulam-Warburton) is analogous to A170927 (for toothpicks). Further, the lower limit of A147562(n)/n^2 evidently approaches twice the constant given in A195853.

Note that all values in this sequence are odd and that a(n)=2*a(n-1)+1 or a(n)=2*a(n-1)-1. - Robert Price, Aug 14 2015

REFERENCES

D. Applegate, O. E. Pol and N. J. A. Sloane, The toothpick sequence and other sequences from cellular automata, Congressus Numerantium, v. 206 (2010) 157-191.

LINKS

Robert Price, Table of n, a(n) for n = 0..291

D. Applegate, O. E. Pol and N. J. A. Sloane, The toothpick sequence and other sequences from cellular automata; also available at arXiv:1004.3036v2, [math.CO], 2010.

Steven R. Finch, Toothpicks and Live Cells, July 21, 2015. [Cached copy, with permission of the author]

CROSSREFS

KEYWORD

nonn

AUTHOR

Steven Finch, Jul 20 2015

STATUS

approved