cosh(arctan(x)*tan(x))=1+12/4!*x^4+10640/8!*x^8-241920/10!*x^10...

A012453

cosh(arctan(x)*tan(x))=1+12/4!*x^4+10640/8!*x^8-241920/10!*x^10...

Terms

    a(0) =1a(1) =0a(2) =12a(3) =0a(4) =10640a(5) =-241920a(6) =75278016a(7) =-7539051520

External references