956483domain: NAppears in sequencesLargest n-digit number k such that k+1 as well as 1 + the product of digits of k are squares greater than 1.at n=5A089698a(1) = 2, a(n) = k - 1, where k is the least number greater than a(n-1) such that rad(k) | a(n-1), where rad(n) = A007947(n).at n=16A365413