E.g.f. cosh(sin(arctan(x))) = cosh(x/sqrt(1+x^2)) (even powers only).

A012027

E.g.f. cosh(sin(arctan(x))) = cosh(x/sqrt(1+x^2)) (even powers only).

Terms

    a(0) =1a(1) =1a(2) =-11a(3) =301a(4) =-15287a(5) =1239481a(6) =-146243459a(7) =23567903269

External references