exp(arctanh(x) + arctan(x)) = 1 + 2*x + 4/2!*x^2 + 8/3!*x^3 + 16/4!*x^4 + 80/5!*x^5 +...

A013174

exp(arctanh(x) + arctan(x)) = 1 + 2*x + 4/2!*x^2 + 8/3!*x^3 + 16/4!*x^4 + 80/5!*x^5 +...

Terms

    a(0) =1a(1) =2a(2) =4a(3) =8a(4) =16a(5) =80a(6) =640a(7) =4160a(8) =21760a(9) =177920a(10) =2291200a(11) =25548800a(12) =223436800a(13) =2560563200a(14) =44438118400a(15) =702660608000

External references