

A089484


Number of configurations of the sliding block 15puzzle 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
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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, 15Puzzle Optimal Solver
R. E. Korf and P. Schultze, LargeScale Parallel BreadthFirst 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



