a(n) = Sum_{k=0..n} binomial(2*k,k) * binomial(2*n-k-1,n-k).
A386940
a(n) = Sum_{k=0..n} binomial(2*k,k) * binomial(2*n-k-1,n-k).
Terms
- a(0) =1a(1) =3a(2) =13a(3) =60a(4) =285a(5) =1378a(6) =6748a(7) =33372a(8) =166365a(9) =834900a(10) =4213638a(11) =21368724a(12) =108820764a(13) =556184580a(14) =2851679620a(15) =14661848560a(16) =75568345821a(17) =390330333402
External references
- oeis: A386940