78561domain: NAppears in sequencesStirling numbers of the first kind: s(n+2, n).at n=27A000914Even coefficients in expansion of e.g.f. sec(arcsin(arctan(x))).at n=5A012097Expansion of e.g.f. exp(arctanh(arctan(x))).at n=10A012260Ordered Stirling numbers S1(n,k) >= 0.at n=37A193245