156251domain: NAppears in sequencesNumbers that are the sum of 3 positive 7th powers.at n=30A003370Number of base-2 strong pseudoprimes (A001262) less than 10^n.at n=13A055552a(n) = 2*5^n+1.at n=7A199212Numbers that are the concatenation of a square and a cube, and also the concatenation of a cube and a square.at n=22A363835