OFFSET
0,2
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..690
FORMULA
a(n)=sum{k=0..n, sum{j=0..n-k, C((k-1)*(n-k)-(k-2)*j, j)*C(j, n-k-j)}}
MATHEMATICA
A110542[n_] := Sum[Sum[Binomial[(k - 1)*(n - k) - (k - 2)*j, j]* Binomial[j, n - k - j], {j, 0, n - k}], {k, 0, n}]; Table[A110542[n], {n, 0, 50}] (* G. C. Greubel, Aug 31 2017 *)
PROG
(PARI) for(n=0, 20, print1(sum(k=0, n, sum(j=0, n-k, binomial((k-1)*(n-k) -(k-2)*j, j)*binomial(j, n-k-j))), ", ")) \\ G. C. Greubel, Aug 31 2017
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Paul Barry, Jul 25 2005
STATUS
approved