a(n) = Sum_{k=0..n} binomial(n,k) * binomial(4*n+2*k,k).

A387427

a(n) = Sum_{k=0..n} binomial(n,k) * binomial(4*n+2*k,k).

Terms

    a(0) =1a(1) =7a(2) =87a(3) =1219a(4) =17999a(5) =273752a(6) =4243755a(7) =66669512a(8) =1057724927a(9) =16908237391a(10) =271909010752

External references