a(n) = (2*n)!*(2*n+1)!/n! = n!*A000909(n), n=0,1...
A161149
a(n) = (2*n)!*(2*n+1)!/n! = n!*A000909(n), n=0,1...
Terms
- a(0) =1a(1) =12a(2) =1440a(3) =604800a(4) =609638400
External references
- oeis: A161149
A161149
a(n) = (2*n)!*(2*n+1)!/n! = n!*A000909(n), n=0,1...