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%I #8 Aug 16 2015 12:03:39
%S 1,9,54,321,1847,9992,50136,227536,870072,1887748,623800,2644
%N Number of positions that are exactly n moves from the starting position in the 2 X 2 X 2 Rubik cube puzzle.
%C This is the number of positions that can be reached in n moves from the start, but which cannot be reached in fewer than n moves.
%C A puzzle in the Rubik cube family. The total number of distinct positions is 3674160. A half-turn is considered to be one move.
%D D. R. Hofstadter, Metamagical Themas, Basic Books, NY, 1985, p. 359.
%H Mark Longridge, <a href="http://cubeman.org/fullcube.txt">God's Algorithm Calculations for Rubik's Cube...</a>
%H Jaap Scherphuis, <a href="http://www.jaapsch.net/puzzles/">Puzzle Pages</a>
%Y Cf. A079762, A152169.
%K nonn,fini,full
%O 0,2
%A _N. J. A. Sloane_, Feb 20 2003
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