arctanh(sec(x)*tan(x))=x+7/3!*x^3+185/5!*x^5+12367/7!*x^7...

A012798

arctanh(sec(x)*tan(x))=x+7/3!*x^3+185/5!*x^5+12367/7!*x^7...

Terms

    a(0) =1a(1) =7a(2) =185a(3) =12367a(4) =1558865a(5) =316097527a(6) =94003171145

External references