83818

Appears in sequences

• arcsinh(arcsinh(x)*tan(x))=2/2!*x^2+4/4!*x^4-10/6!*x^6-2872/8!*x^8...at n=5A012616
• Expansion of (x^2)/(1-2*x-x^2+x^3)^2.at n=13A189426