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 A015893 #13 Oct 23 2018 05:43:34 %S A015893 1,2,4,7,8,14,28,35,56,91,172,175,616,742,904,946,1204,1267,1288,2275, %T A015893 2486,4795,5551,7288,10396,10696,16426,16471,18536,31675,34126,38872, %U A015893 40132,40775,58618,61075,67768,72136,78604,86296,117656 %N A015893 Numbers k such that k | 7^k + 7. %H A015893 Giovanni Resta, <a href="/A015893/b015893.txt">Table of n, a(n) for n = 1..1200</a> %t A015893 Select[Range[10^5], Mod[PowerMod[7, #, #] + 7, #] == 0 &] (* _Giovanni Resta_, Oct 23 2018 *) %Y A015893 Cf. A006517, A015888, A015889, A015891, A015892, A015897, A015898, A015902, A015903, A015904, A015905, A015906. %K A015893 nonn %O A015893 1,2 %A A015893 _Robert G. Wilson v_ %E A015893 Missing a(2)-a(3) from _Giovanni Resta_, Oct 23 2018