A112579 Number of 3-D arrays of 0's and 1's with plane sums 2.

0, 8, 900, 366336, 378028800, 833156928000, 3477528928742400, 25183876050321408000, 296058177312000019660800, 5362158372805111867637760000, 143458227395428379364635443200000

Offset

1,2

References

P. J. Cameron and T. W. Mueller, Decomposable functors and the exponential principle, II, in preparation

Links

Table of n, a(n) for n=1..11.

P. J. Cameron and T. W. Mueller, Decomposable functors and the exponential principle, II, arXiv:0911.3760 [math.CO]

Formula

a(n) = b(n) + Sum (k/n)*(n choose k)^3*b(k)*a(n-k), where b(n) counts indecomposable arrays (A112578).

Example

a(2)=8: six pairs of opposite edges and two inscribed tetrahedra.

Crossrefs

Cf. A001499 (2-D case), A112578, A112580.

Sequence in context: A265239 A290023 A112578 * A064072 A146536 A189646

Adjacent sequences: A112576 A112577 A112578 * A112580 A112581 A112582

Keyword

nonn,easy

Author

Peter J. Cameron, Sep 14 2005

Status

approved