tan(cosh(x)*arctan(x))=x+3/3!*x^3+45/5!*x^5+1071/7!*x^7+69177/9!*x^9...

A012769

tan(cosh(x)*arctan(x))=x+3/3!*x^3+45/5!*x^5+1071/7!*x^7+69177/9!*x^9...

Terms

    a(0) =1a(1) =3a(2) =45a(3) =1071a(4) =69177a(5) =3986939a(6) =609782693a(7) =60159520487

External references