A116269 Numbers k such that k*(k+7) gives the concatenation of two numbers m and m-3.
87, 3675, 6319, 8785, 48742, 51252, 87616, 3762553, 6237441, 9217099, 3266298273, 3520463763, 6479536231, 6733701721, 8063694647, 8317860137, 4689524709430934473, 5310475290569065521, 7416797436703661746
Offset: 1