OFFSET
0,3
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..25
FORMULA
a(n) = A262809(n,n).
a(n) ~ n^(n^2 - n/2 + 1) / (exp(1/12) * 2^(n + log(2)/24) * Pi^((n-1)/2) * log(2)^(n^2+1)). - Vaclav Kotesovec, Mar 23 2016
EXAMPLE
a(2) = 13: [(2,2),(1,2),(0,2),(0,1),(0,0)], [(2,2),(1,2),(0,1),(0,0)], [(2,2),(1,2),(1,1),(0,1),(0,0)], [(2,2),(1,2),(1,1),(0,0)], [(2,2),(1,2),(1,1),(1,0),(0,0)], [(2,2),(2,1),(1,1),(0,1),(0,0)], [(2,2),(2,1),(1,1),(0,0)], [(2,2),(2,1),(1,1),(1,0),(0,0)], [(2,2),(2,1),(2,0),(0,1),(0,0)], [(2,2),(2,1),(1,0),(0,0)], [(2,2),(1,1),(0,1),(0,0)], [(2,2),(1,1),(0,0)], [(2,2),(1,1),(1,0),(0,0)].
MATHEMATICA
Flatten[{1, Table[Sum[Sum[(-1)^i*Binomial[j, i]*Binomial[j - i, n]^n, {i, 0, j}], {j, 0, n^2}], {n, 1, 10}]}] (* Vaclav Kotesovec, Mar 23 2016 *)
PROG
(PARI) a(n)=sum(j=0, n^2, sum(i=0, j, (-1)^i*binomial(j, i)*binomial(j - i, n)^n)) \\ Charles R Greathouse IV, Jul 29 2016
CROSSREFS
KEYWORD
nonn,nice
AUTHOR
Alois P. Heinz, Oct 02 2015
STATUS
approved