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

A360057

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

Terms

    a(0) =1a(1) =6a(2) =27a(3) =125a(4) =644a(5) =3643a(6) =21974a(7) =138395a(8) =898695a(9) =5970927a(10) =40386209a(11) =277127148a(12) =1924349756a(13) =13496536510a(14) =95467320600a(15) =680260392219

External references