-283500

Appears in sequences

• sech(log(x+1)-arctanh(x))=1-3/4!*x^4-90/6!*x^6-4095/8!*x^8...at n=5A013304
• E.g.f. A(x) satisfies: d/dx A(x) = 1 + (1/(1 + x)) * A(x/(1 + x)).at n=8A331661