a(n) = Sum_{k = 0..n} (-4)^(n-k)*binomial(n,k)*binomial(3*n+2*k,2*k)* binomial(2*k,k).
A363988
a(n) = Sum_{k = 0..n} (-4)^(n-k)*binomial(n,k)*binomial(3*n+2*k,2*k)* binomial(2*k,k).
Terms
- a(0) =1a(1) =16a(2) =828a(3) =53836a(4) =3879404a(5) =296396016a(6) =23517939996
External references
- oeis: A363988