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A112579
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Number of 3-D arrays of 0's and 1's with plane sums 2.
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2
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0, 8, 900, 366336, 378028800, 833156928000, 3477528928742400, 25183876050321408000, 296058177312000019660800, 5362158372805111867637760000, 143458227395428379364635443200000
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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REFERENCES
| P. J. Cameron and T. W. Mueller, Decomposable functors and the exponential principle, II, in preparation
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FORMULA
| a(n) = b(n) + Sum (k/n)*(n choose k)^3*b(k)*a(n-k), where b(n) counts indecomposable arrays (A112578)
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EXAMPLE
| a(2)=8: six pairs of opposite edges and two inscribed tetrahedra
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CROSSREFS
| Cf. A001499 (2-D case), A112578, A112580.
Sequence in context: A175411 A027725 A112578 * A064072 A146536 A189646
Adjacent sequences: A112576 A112577 A112578 * A112580 A112581 A112582
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KEYWORD
| nonn,easy
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AUTHOR
| Peter J. Cameron (p.j.cameron(AT)qmul.ac.uk), Sep 14 2005
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