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A136278 Number of n X n Life configurations that are "still Life"s (unchanged in one step). 2
1, 2, 12, 83, 417, 3928, 127425, 4782725, 285886827, 29305144137, 5078448221965, 1689709601427846, 898792333612812818, 812773906928265250254, 1327574905899625395329686 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
These counts have not been reduced to take into account the symmetries of the board.
REFERENCES
E. R. Berlekamp, J. H. Conway and R. K. Guy, Winning Ways, Academic Press, NY, 2 vols., 1982; see Chapter 25.
D. E. Knuth, The Art of Computer Programming, Vol. 4A, Section 7.1.4.
LINKS
EXAMPLE
The 83 still lifes for n=4 have well-known names, explained in the book by Berlekamp et al.: 9 are blocks, 12 are snakes, 4 are tubs, 16 are boats, 8 are ships, 8 are aircraft carriers, 4 are beehives, 8 are eaters, 4 are loaves, 2 are barges, 4 are longboats, 2 are long barges, 1 is the pond and the other one is empty.
CROSSREFS
Sequence in context: A235348 A052864 A355378 * A130464 A319326 A214765
KEYWORD
nonn
AUTHOR
Don Knuth, Mar 26 2008
EXTENSIONS
a(1) and a(7) corrected and a(11)-(15) added by Tomas Rokicki, Oct 29 2010
STATUS
approved

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Last modified March 29 09:32 EDT 2024. Contains 371268 sequences. (Running on oeis4.)