a(n) = (1/n) * Sum_{k=0..n-1} binomial(n+k-1,k) * binomial(4*n,n-k-1) * (n-3)^k.
A366204
a(n) = (1/n) * Sum_{k=0..n-1} binomial(n+k-1,k) * binomial(4*n,n-k-1) * (n-3)^k.
Terms
- a(0) =1a(1) =3a(2) =22a(3) =305a(4) =6873a(5) =223300a(6) =9609372a(7) =517122117a(8) =33450100420
External references
- oeis: A366204