a(n) = (2*n+1)!*(2*n-2)!/((n-1)!*(n!)^2*6).
A157713
a(n) = (2*n+1)!*(2*n-2)!/((n-1)!*(n!)^2*6).
Terms
- a(0) =1a(1) =10a(2) =280a(3) =12600a(4) =776160a(5) =60540480a(6) =5708102400a(7) =630745315200
External references
- oeis: A157713
A157713
a(n) = (2*n+1)!*(2*n-2)!/((n-1)!*(n!)^2*6).