-log(cos(arctanh(x)))=1/2!*x^2+10/4!*x^4+280/6!*x^6+15440/8!*x^8...

A012243

-log(cos(arctanh(x)))=1/2!*x^2+10/4!*x^4+280/6!*x^6+15440/8!*x^8...

Terms

    a(0) =1a(1) =10a(2) =280a(3) =15440a(4) =1412480a(5) =193606400a(6) =37162777600

External references