cos(arctanh(x)+arctan(x))=1-4/2!*x^2+16/4!*x^4-640/6!*x^6+21760/8!*x^8...

A013179

cos(arctanh(x)+arctan(x))=1-4/2!*x^2+16/4!*x^4-640/6!*x^6+21760/8!*x^8...

Terms

    a(0) =1a(1) =-4a(2) =16a(3) =-640a(4) =21760a(5) =-2291200a(6) =223436800a(7) =-44438118400

External references