Coefficients of x^n in the n-th iteration of the g.f. of A120010: a(n) = [x^n] { (1-sqrt(1-4*x))/2 o x/(1-n*x) o (x-x^2) } for n>=1.
A120020
Coefficients of x^n in the n-th iteration of the g.f. of A120010: a(n) = [x^n] { (1-sqrt(1-4*x))/2 o x/(1-n*x) o (x-x^2) } for n>=1.
Terms
- a(0) =1a(1) =2a(2) =9a(3) =68a(4) =710a(5) =9348a(6) =148085a(7) =2740672a(8) =58033953a(9) =1383923040a(10) =36705564368
External references
- oeis: A120020