(2*n)!-Sum ((-1)^(i+1)*binomial(n,i)*2^i*(2*n-1)!,i=1..n).
A006548
(2*n)!-Sum ((-1)^(i+1)*binomial(n,i)*2^i*(2*n-1)!,i=1..n).
Terms
- a(0) =0a(1) =24a(2) =480a(3) =40320a(4) =2903040a(5) =479001600a(6) =74724249600
External references
- oeis: A006548
A006548
(2*n)!-Sum ((-1)^(i+1)*binomial(n,i)*2^i*(2*n-1)!,i=1..n).