Expansion of tanh(tan(x))*cos(x).

A009809

Expansion of tanh(tan(x))*cos(x).

Terms

    a(0) =1a(1) =-3a(2) =-3a(3) =49a(4) =2905a(5) =83589a(6) =-334059a(7) =-351159815a(8) =-39776495567

External references