A137465 1 concatenated with n n's concatenated with 1.

111, 1221, 13331, 144441, 1555551, 16666661, 177777771, 1888888881, 19999999991, 1101010101010101010101, 111111111111111111111111, 11212121212121212121212121, 1131313131313131313131313131, 114141414141414141414141414141, 11515151515151515151515151515151

Offset

1,1

Links

Table of n, a(n) for n=1..15.

Example

a(7) = 177777771.

Mathematica

Table[FromDigits[Join[{1}, Flatten[IntegerDigits/@Table[n, {n}]], {1}]], {n, 15}] (* Harvey P. Dale, Apr 19 2013 *)

Crossrefs

Cf. A000461 (concatenate n n times).

Sequence in context: A102782 A302475 A303256 * A101152 A250145 A075859

Adjacent sequences: A137462 A137463 A137464 * A137466 A137467 A137468

Keyword

easy,nonn,base

Author

Ctibor O. Zizka, Apr 19 2008

Extensions

More terms from Harvey P. Dale, Apr 19 2013

Status

approved