A116284 n times n+9 gives the concatenation of two numbers m and m-1.
32, 60, 804, 4778, 5214, 7406, 48208886, 51791106, 77620651, 4291816088, 4482541430, 5517458562, 5708183904, 9036996876, 9737360643, 3579205562000136225339579331, 3939042613182345526485238179
Offset: 1