A260239 Consider the 2^n values of A147562(i)/i^2 for 2^n <= i < 2^(n+1); a(n) = value of i where this quantity is minimized.

1, 3, 5, 11, 23, 45, 91, 183, 365, 731, 1461, 2923, 5847, 11693, 23387, 46775, 93549, 187099, 374197, 748395, 1496791, 2993581, 5987163, 11974327, 23948653, 47897307, 95794615, 191589229, 383178459, 766356917, 1532713835, 3065427671

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

Cf. A139250, A147562, A170927, A195853.

Sequence in context: A155753 A133914 A169913 * A023223 A106086 A072828

Adjacent sequences: A260236 A260237 A260238 * A260240 A260241 A260242

Keyword

nonn

Author

Steven Finch, Jul 20 2015

Status

approved