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A090031
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Number of configurations of the 5 X 5 variant of sliding block 15-puzzle ("24-puzzle") that require a minimum of n moves to be reached, starting with the empty square in one of the corners.
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6
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1, 2, 4, 10, 26, 64, 159, 366, 862, 1904, 4538, 10238, 24098, 53186, 123435, 268416, 616374, 1326882, 3021126, 6438828, 14524718, 30633586, 68513713, 143106496, 317305688, 656178756, 1442068376, 2951523620
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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COMMENTS
| The 15-block puzzle is often referred to (incorrectly) as Sam Loyd's 15-Puzzle.
114 <= (number of last sequence term) <= 210. Sum of sequence terms=A088020(5)/2.
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REFERENCES
| See A087725 for references.
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LINKS
| Hugo Pfoertner, Configuration counts for n*n sliding block puzzles.
Tomas Rokicki, comment in Twenty-Four puzzle, some observations
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PROG
| See link in A089473.
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CROSSREFS
| Cf. A087725, A089473, A089484, A090032.
Sequence in context: A100605 A183947 A154322 * A055775 A090032 A090377
Adjacent sequences: A090028 A090029 A090030 * A090032 A090033 A090034
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KEYWORD
| fini,hard,nonn
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AUTHOR
| Hugo Pfoertner (hugo(AT)pfoertner.org), Nov 25 2003
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EXTENSIONS
| Added more terms, Tomas Rokicki, Aug 09 2011.
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