A248038 3n concatenated with itself.

33, 66, 99, 1212, 1515, 1818, 2121, 2424, 2727, 3030, 3333, 3636, 3939, 4242, 4545, 4848, 5151, 5454, 5757, 6060, 6363, 6666, 6969, 7272, 7575, 7878, 8181, 8484, 8787, 9090, 9393, 9696, 9999, 102102, 105105, 108108, 111111, 114114, 117117, 120120, 123123

Offset: 1

Author

Larry Guindine, Sep 30 2014

Keywords

• nonn
• base
• easy

Programs

Mathematica

#*10^IntegerLength[#]+#&/@(3*Range[50]) (* Harvey P. Dale, Jan 14 2019 *)

Extensions

Definition edited by N. J. A. Sloane, Sep 30 2014

More terms from Alois P. Heinz, Sep 30 2014