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 A015905 #15 Oct 23 2018 05:45:42 %S A015905 1,2,13,14,26,182,286,2626,2926,8866,10186,57226,62686,118378,185653, %T A015905 187838,284662,396526,689546,792946,927706,1110214,1140686,1501526, %U A015905 1943266,2034406,2402686,2427706,2759926,3032926,4450706,6586426,6849766,7319026,9357518 %N A015905 Numbers k such that k | 13^k + 13. %H A015905 Giovanni Resta, <a href="/A015905/b015905.txt">Table of n, a(n) for n = 1..400</a> %t A015905 Select[Range[10^6], Mod[13 + PowerMod[13, #, #], #] == 0 &] (* _Giovanni Resta_, Oct 21 2018 *) %Y A015905 Cf. A006517, A015888, A015889, A015891, A015892, A015893, A015897, A015898, A015902, A015903, A015904, A015906. %K A015905 nonn %O A015905 1,2 %A A015905 _Robert G. Wilson v_ %E A015905 Missing a(2) and a(33)-a(35) from _Giovanni Resta_, Oct 21 2018