OFFSET
0,5
COMMENTS
A pattern is said to have stabilized if it consists entirely of a (possibly empty) periodic component and zero or more spaceships, such that the spaceships will never interact with each other or with the periodic part.
LINKS
Eric M. Schmidt, Table of n, a(n) for n = 0..1000
LifeWiki, One cell thick pattern
Eric M. Schmidt, C++ code to compute this sequence
Eric Weisstein's World of Mathematics, Game of Life
EXAMPLE
From Eric M. Schmidt, Aug 15 2012: (Start)
A 10-cell straight line evolves into a periodic pattern (the pentadecathlon) in two steps. Therefore a(10) = 2. (Based on example in A098720)
A 33-cell straight line evolves, in 387 steps, into a pattern consisting of a periodic component and four gliders. The pattern has not yet stabilized since the gliders will eventually collide.
A 56-cell straight line evolves, in 246 steps, into a pattern consisting of a periodic component and four gliders. The gliders will never collide with each other or with the periodic component, so the pattern has stabilized. Thus, a(56) = 246. (End)
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Oct 23 2009, based on a posting by Allan C. Wechsler to the Math Fun Mailing List.
EXTENSIONS
More terms and definition changed by Eric M. Schmidt, Aug 15 2012
STATUS
approved