G.f.: 1 = 1/(1+x) + Sum_{n>=1} a(n)*C(2n,n-1)*x^n* Sum_{k>=0} C(2n+k,k)^2*(-x)^k.
A181168
G.f.: 1 = 1/(1+x) + Sum_{n>=1} a(n)*C(2n,n-1)*x^n* Sum_{k>=0} C(2n+k,k)^2*(-x)^k.
Terms
- a(0) =1a(1) =2a(2) =11a(3) =114a(4) =1892a(5) =45800a(6) =1520535a(7) =66256610a(8) =3666164264a(9) =251038266192
External references
- oeis: A181168