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Search: id:A140521
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| A140521 |
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Number of directed "king tours" on an n X n board. |
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+0
4
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| 1, 6, 32, 5660, 4924128, 45707720232, 3244086234829248, 1923484178952564643368
(list; graph; listen)
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OFFSET
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1,2
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COMMENT
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Or, number of directed Hamiltonian cycles in the graph P_n X P_n.
If the direction of the tour is not taken into account, the numbers for n > 1 must be halved (see A140519).
Computed using ZDDs (ZDD = "reduced, order, zero-suppressed binary decision diagram").
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REFERENCES
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D. E. Knuth, The Art of Computer Programming, Section 7.1.4, in preparation.
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LINKS
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Eric Weisstein's World of Mathematics, King's Tour Graph [From Eric W. Weisstein (eric(AT)weisstein.com), Mar 23 2009]
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CROSSREFS
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Cf. A001230, A140519.
Sequence in context: A121120 A135538 A132548 this_sequence A069065 A073343 A157872
Adjacent sequences: A140518 A140519 A140520 this_sequence A140522 A140523 A140524
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KEYWORD
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nonn
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AUTHOR
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D. E. Knuth, Jul 26 2008
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