arctan(tanh(x)+arctan(x))=2*x-20/3!*x^3+1128/5!*x^5-158112/7!*x^7...

A013144

arctan(tanh(x)+arctan(x))=2*x-20/3!*x^3+1128/5!*x^5-158112/7!*x^7...

Terms

    a(0) =2a(1) =-20a(2) =1128a(3) =-158112a(4) =41334912a(5) =-17364051712

External references