848240domain: NAppears in sequencesList of pairs of consecutive refactorable numbers.at n=22A036898Numbers k such that k and k+1 are both refactorable numbers.at n=11A114617a(n) = 2401*n^2 - 980*n + 99.at n=18A157375Both k and its reverse are one less than a square.at n=20A287389