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A109252
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Number of fair sudoku problems with n given values on a 4 x 4 grid.
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0
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0, 0, 0, 0, 25728, 284160, 1041408, 2141184, 2961024, 2958336, 2204928, 1239552, 522624, 161280, 34560, 4608, 288
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,5
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COMMENTS
| A problem is 'fair' if the given values are sufficient to resolve the entire grid to a unique Sudoku solution. Since a(16) represents problems in which the whole grid is already given, a(16) is necessarily the same as A107739(2).
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EXAMPLE
| An example fair problem with 4 given digits is ?4?2 / ???1 / ???? / ?3??, which has the complete grid 1432 / 3241 / 4123 / 2314 as the only solution. There are 25,728 such fair problems with 4 given digits, so a(4) = 25728.
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CROSSREFS
| Cf. A107739.
Sequence in context: A172926 A172946 A115535 * A142708 A003927 A115494
Adjacent sequences: A109249 A109250 A109251 * A109253 A109254 A109255
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KEYWORD
| fini,full,nonn
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AUTHOR
| Hugo van der Sanden (hv(AT)crypt.org), Aug 19 2005
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