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A178842
a(n) = binomial((n-1)^2, n).
1
0, 0, 4, 126, 4368, 177100, 8347680, 450978066, 27540584512, 1878392407320, 141629804643600, 11703541346076580, 1052134368066259632, 102250849636865496528, 10683770265451303535424, 1194448077521704400002650, 142288257910903254700704000, 17993390003427864738863790640
OFFSET
1,3
COMMENTS
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).
LINKS
MATHEMATICA
a[n_] := Binomial[(n - 1)^2, n]; Array[a, 18] (* Robert G. Wilson v, Jul 25 2010 *)
PROG
(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
CROSSREFS
Cf. A014062 (binomial(n^2, n)).
Sequence in context: A116944 A124260 A253099 * A054053 A348814 A070781
KEYWORD
nonn
AUTHOR
Thomas Young, Jun 17 2010
STATUS
approved