a(n) = (1/2) * Sum_{k=1..n} (-1)^(k-1) * binomial(2*n-k, k) * binomial(n, k) * 2^k * (2*n-2*k)!.
A159960
a(n) = (1/2) * Sum_{k=1..n} (-1)^(k-1) * binomial(2*n-k, k) * binomial(n, k) * 2^k * (2*n-2*k)!.
Terms
- a(0) =1a(1) =10a(2) =292a(3) =16152a(4) =1443616a(5) =189709600a(6) =34420171584
External references
- oeis: A159960