a(n) equals the coefficient of x^n in the (2*n-1)-th iteration of x+x^2 for n>=1.
A194972
a(n) equals the coefficient of x^n in the (2*n-1)-th iteration of x+x^2 for n>=1.
Terms
- a(0) =1a(1) =3a(2) =20a(3) =231a(4) =3864a(5) =85140a(6) =2332616a(7) =76485227a(8) =2921536088a(9) =127421864328
External references
- oeis: A194972