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 A089484 Number of configurations of the sliding block 15-puzzle that require a minimum of n moves to be reached, starting with the empty square in one of the corners. 11
 1, 2, 4, 10, 24, 54, 107, 212, 446, 946, 1948, 3938, 7808, 15544, 30821, 60842, 119000, 231844, 447342, 859744, 1637383, 3098270, 5802411, 10783780, 19826318, 36142146, 65135623, 116238056, 204900019, 357071928, 613926161, 1042022040 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS The last sequence term is a(80). The total number of possible configurations of an m*m sliding block puzzle is (m*m)!/2=A088020(4)/2, therefore Sum_i (i=0..80) a(i)=16!/2=10461394944000. REFERENCES See A087725. LINKS Herman Jamke, Table of n, a(n) for n = 0..80 (complete sequence) Herbert Kociemba, 15-Puzzle Optimal Solver R. E. Korf and P. Schultze, Large-Scale Parallel Breadth-First Search Hugo Pfoertner, Configuration counts for n*n sliding block puzzles. CROSSREFS Cf. A087725, A089473, A090031, A090032, A090164, A090165, A088020. Sequence in context: A094837 A136427 A018114 * A132732 A275447 A095214 Adjacent sequences:  A089481 A089482 A089483 * A089485 A089486 A089487 KEYWORD fini,full,nonn AUTHOR Hugo Pfoertner, Nov 25 2003 EXTENSIONS More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Oct 19 2006 STATUS approved

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Last modified December 7 05:11 EST 2019. Contains 329839 sequences. (Running on oeis4.)