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 A250048 #7 Feb 06 2015 05:54:20
%S A250048 1,6,7,8,9,10,11,37,41,43,44,45,46,47,49,51,53,55,56,58,59,61,63,67,
%T A250048 68,69,70,71,223,224,225,226,227,247,248,249,250,251,259,260,261,262,
%U A250048 263,265,267,269,271,272,274,277,279,281,283,284,285,286,287,295
%N A250048 Numbers n such that m = floor(n/6) is coprime to n and, if nonzero, m is also a term of the sequence.
%C A250048 See the comments in A250040 which all apply, except for the setting of the base, b=6. In particular, they define the property RTC(b).
%H A250048 Stanislav Sykora, <a href="/A250048/b250048.txt">Table of n, a(n) for n = 1..10000</a>
%H A250048 Stanislav Sykora, <a href="https://oeis.org/wiki/File:GeneticThreads.txt">PARI/GP scripts for genetic threads</a>, with code and comments.
%H A250048 Wikipedia, <a href="http://en.wikipedia.org/wiki/Coprime_integers">Coprime integers</a>
%o A250048 (PARI) \\ See A250040 for b=6
%o A250048 (PARI) is_rtc(n, b=6) = {while (((m=gcd(n\b, n)) == 1), if (m == 0, return (1)); if ((n=n\b) == 0, return (1));); return (0);} \\ _Michel Marcus_, Jan 31 2015
%Y A250048 Cf. A250040 (b=10), A250047.
%Y A250048 Other lists of right-truncatable numbers with the property RTC(b): A250036 (b=4), A250038 (b=16), A250042 (b=9), A250044 (b=8), A250046 (b=7), A250050 (b=5).
%K A250048 nonn,base
%O A250048 1,2
%A A250048 _Stanislav Sykora_, Jan 31 2015