a(n) = Sum_{k=0..n} binomial(n,k)*binomial(2*n+k-1,k).
A156894
a(n) = Sum_{k=0..n} binomial(n,k)*binomial(2*n+k-1,k).
Terms
- a(0) =1a(1) =3a(2) =19a(3) =138a(4) =1059a(5) =8378a(6) =67582a(7) =552576a(8) =4563235a(9) =37972290a(10) =317894394a(11) =2674398268a(12) =22590697614a(13) =191475925332
External references
- oeis: A156894