A075842 n 1's followed by n.

11, 112, 1113, 11114, 111115, 1111116, 11111117, 111111118, 1111111119, 111111111110, 1111111111111, 11111111111112, 111111111111113, 1111111111111114, 11111111111111115, 111111111111111116, 1111111111111111117, 11111111111111111118, 111111111111111111119

Offset

1,1

References

J. Earls, On Smarandache Repunit N Numbers, Smarandache Notions Journal, Journal (2004), Vol. 14.1, pp 251-258.

Links

Table of n, a(n) for n=1..19.

Formula

a(n) = (10^n-1)/9*10^L + n, where L is the number of decimal digits of n.

Mathematica

Array[(10^# - 1)/9*10^IntegerLength[#] + # &, 16] (* or *)
Array[FromDigits[ConstantArray[1, #]~Join~IntegerDigits[#]] &, 16] (* Michael De Vlieger, Mar 21 2018 *)

Crossrefs

Cf. A070746.

Sequence in context: A058949 A378022 A119742 * A037535 A065834 A104720

Adjacent sequences: A075839 A075840 A075841 * A075843 A075844 A075845

Keyword

base,easy,nonn,less

Author

Jason Earls, Oct 15 2002

Status

approved