cos(cos(x)-sech(x))=1-560/8!*x^8+50400/10!*x^10-4403520/12!*x^12...

A013487

cos(cos(x)-sech(x))=1-560/8!*x^8+50400/10!*x^10-4403520/12!*x^12...

Terms

    a(0) =1a(1) =0a(2) =0a(3) =0a(4) =-560a(5) =50400a(6) =-4403520a(7) =451651200a(8) =-55603258880

External references