tanh(tanh(x)+arctan(x))=2*x-20/3!*x^3+872/5!*x^5-82848/7!*x^7...

A013148

tanh(tanh(x)+arctan(x))=2*x-20/3!*x^3+872/5!*x^5-82848/7!*x^7...

Terms

    a(0) =2a(1) =-20a(2) =872a(3) =-82848a(4) =13615232a(5) =-3427600128

External references