Coefficients of x^n in the (n+1)-th self-composition of the g.f. of A120009, so that: a(n) = [x^n] { (x-x^2) o x/(1-(n+1)*x) o (1-sqrt(1-4*x))/2 } for n>=1.
A120015
Coefficients of x^n in the (n+1)-th self-composition of the g.f. of A120009, so that: a(n) = [x^n] { (x-x^2) o x/(1-(n+1)*x) o (1-sqrt(1-4*x))/2 } for n>=1.
Terms
- a(0) =1a(1) =3a(2) =16a(3) =120a(4) =1164a(5) =13965a(6) =200960a(7) =3387636a(8) =65644780a(9) =1440018822a(10) =35314018656a(11) =958109355632
External references
- oeis: A120015