A116252 n times n+2 gives the concatenation of two numbers m and m-5.
80, 8156, 9800, 467346, 532653, 998000, 76450588, 99980000, 7801738414, 8593817622, 9208120792, 9999800000, 346667333466, 401461854014, 598538145985, 653332666533, 945207479452, 999998000000, 48349470735059
Offset: 1