a(n) = Sum_{k=0..n} C(3n+k,n-k)*C(4n-k,k).

A184553

a(n) = Sum_{k=0..n} C(3n+k,n-k)*C(4n-k,k).

Terms

    a(0) =1a(1) =6a(2) =79a(3) =1158a(4) =17851a(5) =283246a(6) =4579306a(7) =75013112a(8) =1240774907a(9) =20677408080a(10) =346638007264

External references