a(n) = Sum_{k=0..n} binomial(n,k)^2 * binomial(2*k,k).
A002893
a(n) = Sum_{k=0..n} binomial(n,k)^2 * binomial(2*k,k).
Terms
- a(0) =1a(1) =3a(2) =15a(3) =93a(4) =639a(5) =4653a(6) =35169a(7) =272835a(8) =2157759a(9) =17319837a(10) =140668065a(11) =1153462995a(12) =9533639025a(13) =79326566595a(14) =663835030335
External references
- oeis: A002893