698161domain: NAppears in sequencestan(arcsin(tan(x))) = x+5/3!*x^3+121/5!*x^5+6845/7!*x^7+698161/9!*x^9...at n=4A012077Expansion of e.g.f. exp(arctanh(tan(x))).at n=9A012259Absolute values of numerators of series expansion of sinh(x)/sqrt((cosh(x))^2+(sinh(x))^2) about 0 (odd indexed coefficients only).at n=4A128275