2539107domain: NAppears in sequencesTriangular matrix T where column 0 of T^m equals C(m*3^(n-1), n) at row n for n>=0, m>=0.at n=18A179430Numbers k = p1^e1*p2^e2, with e1 != e2, such that the Euclidean distance between points (p1, e1) and (p2, e2) is an integer.at n=30A387172