Numerators of coefficients in function a(x) such that a(a(x)) = arctan(x).

A048605

Numerators of coefficients in function a(x) such that a(a(x)) = arctan(x).

Terms

    a(0) =1a(1) =-1a(2) =7a(3) =-43a(4) =4489a(5) =-49897a(6) =20130311a(7) =-319053131a(8) =329796121169

External references