9999600005domain: NAppears in sequencesNumbers k such that the concatenation of k with k-4 gives a square.at n=11A115432Numbers k such that k concatenated with k-8 gives the product of two numbers which differ by 4.at n=11A116104Numbers k such that k concatenated with k-5 gives the product of two numbers which differ by 2.at n=11A116121