OFFSET
0,2
LINKS
Harry J. Smith, Table of n, a(n) for n = 0..100
FORMULA
a(n) = 2^(n^2) - binomial(n^2, n+1)*hypergeom([1, -n^2+n+1], [2+n], -1). - Vladeta Jovovic, Jul 08 2003
a(n) ~ exp(n - 1/2) * n^(n - 1/2) / sqrt(2*Pi). - Vaclav Kotesovec, Jun 07 2019
MATHEMATICA
Table[Sum[Binomial[n^2, k], {k, 0, n}], {n, 0, 20}] (* Vincenzo Librandi, Jun 08 2019 *)
PROG
(PARI) { for (n=0, 100, a=0; for (k=0, n, a+=binomial(n^2, k)); write("b066382.txt", n, " ", a) ) } \\ Harry J. Smith, Feb 12 2010
(PARI) a(n) = sum(k=0, n, binomial(n^2, k)); \\ Michel Marcus, Jun 08 2019
(Magma) [&+[Binomial(n^2, k): k in [0..n]]: n in [0..20]]; // Vincenzo Librandi, Jun 08 2019
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Dec 23 2001
STATUS
approved