a(n) = 2*(n^2)!* Product_{k = 1..n-1} k!/(n+k)!.
A033542
a(n) = 2*(n^2)!* Product_{k = 1..n-1} k!/(n+k)!.
Terms
- a(0) =0a(1) =2a(2) =8a(3) =504a(4) =1153152a(5) =168275764800
External references
- oeis: A033542
A033542
a(n) = 2*(n^2)!* Product_{k = 1..n-1} k!/(n+k)!.