a(n) = (1/n) * Sum_{i=0..n-1} C(n,i)*C(n,i+1)*(n-1)^i*n^(n-i) for n>=1, a(0)=1.
A103212
a(n) = (1/n) * Sum_{i=0..n-1} C(n,i)*C(n,i+1)*(n-1)^i*n^(n-i) for n>=1, a(0)=1.
Terms
- a(0) =1a(1) =1a(2) =6a(3) =93a(4) =2380a(5) =85405a(6) =3956106a(7) =224939113a(8) =15175702200
External references
- oeis: A103212