A032613 Concatenation of n and n + 8 or {n,n+8}.
19, 210, 311, 412, 513, 614, 715, 816, 917, 1018, 1119, 1220, 1321, 1422, 1523, 1624, 1725, 1826, 1927, 2028, 2129, 2230, 2331, 2432, 2533, 2634, 2735, 2836, 2937, 3038, 3139, 3240, 3341, 3442, 3543, 3644, 3745, 3846, 3947, 4048, 4149
Offset: 1