419784870961domain: NAppears in sequencesEven coefficients in expansion of e.g.f. cos(x)/sqrt(cos(2*x)).at n=7A012085Expansion of e.g.f. exp(arctanh(tan(x))).at n=14A012259Absolute values of numerators of series expansion of cosh(x)/sqrt((cosh(x))^2+(sinh(x))^2) about 0 (even-indexed coefficients only).at n=7A128274