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 A211449 #4 Apr 11 2012 20:01:09
%S A211449 0,2,2,2,2,2,4,2,2,2,6,2,4,6,2,2,2,2,2,2,8,2,2,8,4,2,2,2,6,8,18,2,4,2,
%T A211449 2,10,6,2,2,2,2,2,2,4,2,2,2,6,2,6,8,2,20,10,32,2,2,2,6,8,6,2,6,2,4,2,
%U A211449 22,16,2,2,8,2,2,2,2,2,2,18,4,4,2,2,10,12
%N A211449 (p-1)/x, where p = prime(n) and x = ord(4,p), the smallest positive integer such that 4^x == 1 mod p.
%H A211449 T. D. Noe, <a href="/A211449/b211449.txt">Table of n, a(n) for n = 1..1000</a>
%t A211449 nn = 4; Table[If[Mod[nn, p] == 0, 0, (p-1)/MultiplicativeOrder[nn, p]], {p, Prime[Range[100]]}]
%Y A211449 Cf. A001917, A094593, A211450, A211451, A211452, A211453, A211454, A006556.
%K A211449 nonn
%O A211449 1,2
%A A211449 _T. D. Noe_, Apr 11 2012