a(n) = Sum_{k = 0..n} (-4)^(n-k)*binomial(n,k)*binomial(4*n+k,k)*binomial(2*k,k).
A363989
a(n) = Sum_{k = 0..n} (-4)^(n-k)*binomial(n,k)*binomial(4*n+k,k)*binomial(2*k,k).
Terms
- a(0) =1a(1) =6a(2) =142a(3) =3732a(4) =108750a(5) =3345256a(6) =106702756a(7) =3491407296a(8) =116430027470
External references
- oeis: A363989