A116234 n times n+3 gives the concatenation of two numbers m and m-8.
75, 3940697271069731588503127963131864400305034239, 4151390954867901940837042502762708788079731026, 4640791465716781132715600310864305127175798261
Offset: 1
Examples
75 * 78 = 58//50, where // denotes concatenation.