A116255 n times n+5 gives the concatenation of two numbers m and m-5.
76, 80917, 91807, 326508, 475023, 524973, 673488, 4323775, 4767130, 5232866, 5676221, 4083911139, 4975000248, 5024999748, 5916088857, 9503960494, 9604950394, 4186904462790, 4313465946773, 5686534053223, 5813095537206
Offset: 1