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 A112578 Number of indecomposable 3-D arrays of 0's and 1's with plane sums 2. 2
 0, 8, 900, 359424, 370828800, 820150272000, 3435918974208000, 24957654229057536000, 294060698786444083200000, 5334667831784096818790400000, 42889554205720574193041408000000 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 REFERENCES P. J. Cameron and T. W. Mueller, Decomposable functors and the exponential principle, II, in preparation LINKS P. J. Cameron and T. W. Mueller, Decomposable functors and the exponential principle, II, arXiv:0911.3760 [math.CO] FORMULA a(1)=0, a(n) = (n!)^2*b(n)/2^n for n>1, where b(0)=1 and sum (n-1 choose k-1)*((2n-2k-1)!!)^2*b(k) = ((2n-1)!!)^2. EXAMPLE a(2)=8: six pairs of opposite edges and two inscribed tetrahedra. CROSSREFS Cf. A010796 (2-D case), A112579, A112580. Sequence in context: A027725 A265239 A290023 * A112579 A064072 A146536 Adjacent sequences:  A112575 A112576 A112577 * A112579 A112580 A112581 KEYWORD nonn,easy AUTHOR Peter J. Cameron, Sep 14 2005 STATUS approved

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Last modified January 17 11:57 EST 2022. Contains 350394 sequences. (Running on oeis4.)