a(n) = Sum_{i=0..n} (2^(i)*(-1)^(i+n)*C(n,i)*C(2*n+i-1,n-1)).
A259554
a(n) = Sum_{i=0..n} (2^(i)*(-1)^(i+n)*C(n,i)*C(2*n+i-1,n-1)).
Terms
- a(0) =1a(1) =7a(2) =52a(3) =403a(4) =3206a(5) =25954a(6) =212738a(7) =1760035a(8) =14666470a(9) =122920642a(10) =1035046816a(11) =8749594462a(12) =74207078908a(13) =631140253072
External references
- oeis: A259554