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 A250046 #10 Jan 29 2015 09:48:00
%S A250046 1,7,8,9,10,11,12,13,50,51,52,53,54,55,57,59,61,64,65,67,68,71,73,78,
%T A250046 79,80,81,82,83,85,89,92,93,94,95,96,97,351,353,358,359,361,362,365,
%U A250046 367,369,372,373,374,375,376,377,379,383,386,387,388,389,391,400
%N A250046 Numbers n such that m = floor(n/7) is coprime to n and, if nonzero, m is also a term of the sequence.
%C A250046 See the comments in A250040 which all apply, except for the setting of the base, b=7. In particular, they define the property RTC(b).
%H A250046 Stanislav Sykora, <a href="/A250046/b250046.txt">Table of n, a(n) for n = 1..10000</a>
%H A250046 Stanislav Sykora, <a href="https://oeis.org/wiki/File:GeneticThreads.txt">PARI/GP scripts for genetic threads</a>, with code and comments.
%H A250046 Wikipedia, <a href="http://en.wikipedia.org/wiki/Coprime_integers">Coprime integers</a>
%o A250046 (PARI) See the link
%o A250046 (PARI) is_rtc(n, b=7) = {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 A250046 Cf. A250040 (b=10), A250047.
%Y A250046 Other lists of right-truncatable numbers with the property RTC(b): A250036 (b=4), A250038 (b=16), A250042 (b=9), A250044 (b=8), A250048 (b=6), A250050 (b=5).
%K A250046 nonn,base
%O A250046 1,2
%A A250046 _Stanislav Sykora_, Jan 15 2015