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 A125556 #11 Nov 18 2017 01:54:33
%S A125556 3,11,61,13,31,241,43,257,271,251,1013,673,157,71,541,241,307,883,
%T A125556 4409,401,1471,463,5843,577,601,2081,271,757,1973,241,2729,2657,4951,
%U A125556 1123,21701,937,32191,14479,3433,641,1723,2521,5849,6689,1531,6257,18143
%N A125556 Smallest prime p = n*m + 1 that divides m^m - 1 for some m > 1.
%C A125556 Corresponding numbers m > 1 such that a(n) divides m^m - 1 are m = (a(n) - 1)/n = {2,5,20,3,6,40,6,32,30,25,92,56,12,5,36,15,18,...}.
%H A125556 Joseph L. Wetherell, <a href="/A125556/b125556.txt">Table of n, a(n) for n = 1..10000</a>
%o A125556 (PARI) a(n) = forprime(p=3, , if (!((p-1) % n) && (m = (p-1)/n) && (m > 1) && !((m^m-1) % p), return (p));); \\ _Michel Marcus_, Nov 18 2017
%Y A125556 Cf. A048861 (n^n - 1).
%K A125556 nonn
%O A125556 1,1
%A A125556 _Alexander Adamchuk_, Jan 22 2007
%E A125556 Corrected a(47) and extended by _Alexander Adamchuk_, May 09 2010