This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A250042 #11 Jan 29 2015 09:49:14
%S A250042 1,9,10,11,12,13,14,15,16,17,82,83,85,86,88,89,91,93,97,100,101,102,
%T A250042 103,104,105,106,107,109,113,115,118,119,120,121,122,123,124,125,127,
%U A250042 129,131,136,137,139,142,143,145,147,149,151,154,155,156,157,158
%N A250042 Numbers n such that m = floor(n/9) is coprime to n and, if nonzero, m is also a term of the sequence.
%C A250042 See the comments in A250040 which all apply, except for the setting of the base, b=9. In particular, they define the property RTC(b).
%H A250042 Stanislav Sykora, <a href="/A250042/b250042.txt">Table of n, a(n) for n = 1..10000</a>
%H A250042 Stanislav Sykora, <a href="https://oeis.org/wiki/File:GeneticThreads.txt">PARI/GP scripts for genetic threads</a>, with code and comments.
%H A250042 Wikipedia, <a href="http://en.wikipedia.org/wiki/Coprime_integers">Coprime integers</a>
%o A250042 (PARI) See the link
%o A250042 (PARI) is_rtc(n, b=9) = {while (((m=gcd(n\b, n)) == 1), if (m == 0, return (1)); if ((n=n\b) == 0, return (1));); return (0);} \\ _Michel Marcus_, Jan 18 2015
%Y A250042 Cf. A250040 (b=10), A250043.
%Y A250042 Other lists of right-truncatable numbers with the property RTC(b): A250036 (b=4), A250038 (b=16), A250044 (b=8), A250046 (b=7), A250048 (b=6), A250050 (b=5).
%K A250042 nonn,base
%O A250042 1,2
%A A250042 _Stanislav Sykora_, Jan 15 2015