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A178842
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a(n) = binomial((n-1)^2, n).
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1
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0, 0, 4, 126, 4368, 177100, 8347680, 450978066, 27540584512, 1878392407320, 141629804643600, 11703541346076580, 1052134368066259632, 102250849636865496528, 10683770265451303535424, 1194448077521704400002650, 142288257910903254700704000, 17993390003427864738863790640
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OFFSET
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1,3
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COMMENTS
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Number of ways to place n objects in an (n-1) X (n-1) array (e.g., the number of ways to arrange stars in a flag's field pattern).
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LINKS
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G. C. Greubel, Table of n, a(n) for n = 1..250
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MATHEMATICA
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a[n_] := Binomial[(n - 1)^2, n]; Array[a, 18] (* Robert G. Wilson v, Jul 25 2010 *)
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PROG
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(PARI) vector(20, n, binomial((n-1)^2, n)) \\ G. C. Greubel, Jan 21 2019
(Magma) [Binomial((n-1)^2, n): n in [1..20]]; // G. C. Greubel, Jan 21 2019
(Sage) [binomial((n-1)^2, n) for n in (1..20)] # G. C. Greubel, Jan 21 2019
(GAP) List([1..20], n -> Binomial((n-1)^2, n)); # G. C. Greubel, Jan 21 2019
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CROSSREFS
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Cf. A014062 (binomial(n^2, n)).
Sequence in context: A116944 A124260 A253099 * A054053 A348814 A070781
Adjacent sequences: A178839 A178840 A178841 * A178843 A178844 A178845
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KEYWORD
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nonn
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AUTHOR
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Thomas Young, Jun 17 2010
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STATUS
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approved
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