a(n) = Sum_{k=0..n} binomial(n,k)*binomial(n^2+k,k).
A306280
a(n) = Sum_{k=0..n} binomial(n,k)*binomial(n^2+k,k).
Terms
- a(0) =1a(1) =3a(2) =26a(3) =416a(4) =9708a(5) =297662a(6) =11306572a(7) =512307336a(8) =26968496504
External references
- oeis: A306280