a(n) = Sum{k=0..n} binomial(n,k)^2*C(k), where C() = A000108() are the Catalan numbers.
A086618
a(n) = Sum{k=0..n} binomial(n,k)^2*C(k), where C() = A000108() are the Catalan numbers.
Terms
- a(0) =1a(1) =2a(2) =7a(3) =33a(4) =183a(5) =1118a(6) =7281a(7) =49626a(8) =349999a(9) =2535078a(10) =18758265a(11) =141254655a(12) =1079364105a(13) =8350678170a(14) =65298467487a(15) =515349097713
External references
- oeis: A086618