3049800625domain: NAppears in sequencesa(n) = (10*n + 5)^4.at n=23A017332a(n) = (11*n + 4)^4.at n=21A017440a(n) = (12*n + 7)^4.at n=19A017608RF(5): refactorable numbers with smallest prime factor 5.at n=15A120320