tanh(tan(x)-arctan(x)) = 4/3!*x^3 - 8/5!*x^5 + 992/7!*x^7 - 68224/9!*x^9 + ...

A013445

tanh(tan(x)-arctan(x)) = 4/3!*x^3 - 8/5!*x^5 + 992/7!*x^7 - 68224/9!*x^9 + ...

Terms

    a(0) =4a(1) =-8a(2) =992a(3) =-68224a(4) =5165312a(5) =-1019810816a(6) =186916489216

External references