a(n) = Sum_{k=0..n} binomial(4*n+2*k+2,n-k).
A390473
a(n) = Sum_{k=0..n} binomial(4*n+2*k+2,n-k).
Terms
- a(0) =1a(1) =7a(2) =58a(3) =503a(4) =4456a(5) =39969a(6) =361473a(7) =3288412a(8) =30048831a(9) =275540020a(10) =2533770713a(11) =23354149592a(12) =215682938096
External references
- oeis: A390473