a(n) = Sum_{k=0..n} binomial(n,k) * binomial(n*k,k) / ((n-1)*k + 1).
A378327
a(n) = Sum_{k=0..n} binomial(n,k) * binomial(n*k,k) / ((n-1)*k + 1).
Terms
- a(0) =1a(1) =2a(2) =5a(3) =25a(4) =257a(5) =4361a(6) =104425a(7) =3241316a(8) =123865313a(9) =5628753361a(10) =296671566941
External references
- oeis: A378327