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A089520 In Conway's Game of Life, the number of steps it takes for an n X n square, in which all the cells are in the "on" state, to die out or start to cycle, or -1 if there is no cycle.

%I A089520 #24 Jul 07 2022 02:03:24
%S A089520 1,0,5,4,11,5,5,6,16,17,32,9,18,9,22,11,33,17,20,12,26,13,48,15,46,26,
%T A089520 295,45,154,38,62,309,38,87,78,53,96,150,641,69,82,265,216,70,70,70,
%U A089520 120,401,107,78,70,351,318,109,297,95,122,-1,-1,85,232,294,127
%N A089520 In Conway's Game of Life, the number of steps it takes for an n X n square, in which all the cells are in the "on" state, to die out or start to cycle, or -1 if there is no cycle.
%C A089520 The -1 terms for n = 58, 59, 80, 92, 95, 96, 98, 99, 100 correspond to starting n x n squares that produce 8 gliders (16 for n = 99) that go off to infinity, hence never reaching a cycle. - _Michael S. Branicky_, Jul 06 2022
%H A089520 Michael S. Branicky, <a href="/A089520/b089520.txt">Table of n, a(n) for n = 1..100</a>
%H A089520 Michael S. Branicky, <a href="/A089520/a089520.py.txt">Python program and utilities.</a>
%H A089520 D. Griffeath, <a href="https://web.archive.org/web/20210512211113/http://psoup.math.wisc.edu/Life32.html">Life32 by Johan Bontes</a>.
%H A089520 Nathaniel Johnston, <a href="https://conwaylife.com/">ConwayLife.com</a>.
%H A089520 S. Silver, <a href="https://conwaylife.com/ref/lexicon/lex_home.htm">Life Lexicon</a>.
%e A089520 a(1) = 1 since a single cell is switched off on step 1.
%e A089520 a(2) = 0 since a block is cyclic to start with: 0th = 1st generation.
%e A089520 a(3) = 5 since a cycle starts there: 5th = 7th generation.
%Y A089520 Cf. A019473, A086993.
%K A089520 sign
%O A089520 1,3
%A A089520 Anne M. Donovan (anned3005(AT)aol.com), Nov 05 2003
%E A089520 More terms from _John W. Layman_, Nov 07 2003
%E A089520 39 more terms from _Rick L. Shepherd_, Jun 04 2004
%E A089520 Name edited, a(58) and a(59) changed, and a(61) and beyond from _Michael S. Branicky_, Jul 06 2022