70266domain: NAppears in sequencesNumbers k such that (k, sigma(k)) lies on a circle with integral radius centered at the origin, i.e., k^2 + sigma(k)^2 is a square.at n=33A066764p-INVERT of (1,1,1,1,1,...), where p(S) = 1 - S^3 - S^6.at n=16A290997Number of canonical 3-polytopes of size n.at n=12A319959