-100090043

Appears in sequences

• cos(sec(x)*arctanh(x))=1-1/2!*x^2-19/4!*x^4-565/6!*x^6-24743/8!*x^8...at n=6A012845
• Expansion of e.g.f.: exp(sech(x)*arctan(x))=1+x+1/2!*x^2-4/3!*x^3-19/4!*x^4+20/5!*x^5...at n=12A012879