a(n) = Sum_{k=0..n} C(2*k, k)^2 * C(n+k, n-k).
A243945
a(n) = Sum_{k=0..n} C(2*k, k)^2 * C(n+k, n-k).
Terms
- a(0) =1a(1) =5a(2) =49a(3) =605a(4) =8281a(5) =120125a(6) =1809025a(7) =27966125a(8) =440790025a(9) =7051890125a(10) =114160867129
External references
- oeis: A243945