a(n) = Sum_{k=0..n} binomial(n+k-1,k) * binomial(2*n+k-1,n-k).

A378460

a(n) = Sum_{k=0..n} binomial(n+k-1,k) * binomial(2*n+k-1,n-k).

Terms

    a(0) =1a(1) =2a(2) =14a(3) =107a(4) =854a(5) =6997a(6) =58337a(7) =492459a(8) =4195910a(9) =36008585a(10) =310797519a(11) =2695146412a(12) =23462692889a(13) =204927930573

External references