a(n) = [x^n] G(n-1,x) where G(n,x) is the n-th iteration of G(1,x) = x/(1-x+x^2), so that G(n,x) = G(n-1, G(1,x)) with G(0,x)=x.

A242573

a(n) = [x^n] G(n-1,x) where G(n,x) is the n-th iteration of G(1,x) = x/(1-x+x^2), so that G(n,x) = G(n-1, G(1,x)) with G(0,x)=x.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =6a(4) =24a(5) =120a(6) =702a(7) =4445a(8) =27812a(9) =187911a(10) =4154105a(11) =226545132a(12) =11811552612a(13) =567839904255

External references