a(n) = f(3*n)/(f(n-1)*f(n)*f(n+1)), where f(k) = k!.
A248707
a(n) = f(3*n)/(f(n-1)*f(n)*f(n+1)), where f(k) = k!.
Terms
- a(0) =3a(1) =60a(2) =1260a(3) =27720a(4) =630630a(5) =14702688a(6) =349188840a(7) =8413788240a(8) =205086088350
External references
- oeis: A248707