91421domain: NAppears in sequencesn*10^4-1, n*10^4-3, n*10^4-7 and n*10^4-9 are all prime.at n=25A064978Centered truncated octahedral numbers: the number of integer triples (x,y,z) such that max(|x|,|y|,|z|) <= 2n and |x|+|y|+|z| <= 3n.at n=14A371515