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 A015963 #21 Apr 10 2020 21:42:48 %S A015963 1,2,7,10,34,49,50,170,203,250,343,578,850,1250,1421,2401,2890,4210, %T A015963 4250,5887,6010,6250,6410,9826,9947,11977,14450,16807,21050,21250, %U A015963 30050,31250,32050,34714,41209,49130,69629,71570,72250,83839,102170 %N A015963 Numbers k such that k | 13^k + 1. %H A015963 Seiichi Manyama, <a href="/A015963/b015963.txt">Table of n, a(n) for n = 1..300</a> %t A015963 Select[Range[102170], Divisible[13^# + 1, #] &] (* _Robert Price_, Apr 10 2020 *) %Y A015963 Solutions to 13^n == k (mod n): this sequence (k=-1), A116621 (k=1), A116622 (k=2), A116629 (k=3), A116630 (k=4), A116611 (k=5), A116631 (k=6), A116632 (k=7), A295532 (k=8), A116636 (k=9), A116620 (k=10), A116638 (k=11), A116639 (k=15). %Y A015963 Column k=13 of A333429. %K A015963 nonn %O A015963 1,2 %A A015963 _Robert G. Wilson v_