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
G. C. Greubel, Table of n, a(n) for n = 1..250
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
KEYWORD
nonn
AUTHOR
Thomas Young, Jun 17 2010
STATUS
approved