cos(tan(arcsinh(x)))=1-1/2!*x^2-3/4!*x^4-21/6!*x^6+185/8!*x^8...

A012163

cos(tan(arcsinh(x)))=1-1/2!*x^2-3/4!*x^4-21/6!*x^6+185/8!*x^8...

Terms

    a(0) =1a(1) =-1a(2) =-3a(3) =-21a(4) =185a(5) =-9641a(6) =1668021a(7) =-192801597a(8) =42064398961

External references