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 A240663 #4 Apr 15 2014 02:36:30
%S A240663 0,1,2,0,5,2,4,3,0,14,0,6,10,7,0,26,29,10,11,0,0,0,41,0,8,50,0,53,6,
%T A240663 14,0,65,34,23,74,0,26,27,0,86,89,30,0,16,98,0,35,0,113,38,0,0,4,25,8,
%U A240663 0,134,0,46,35,47,146,17,0,26,158,5,0,173,58,44,0,0,62
%N A240663 Least k such that 8^k == -1 (mod prime(n)), or 0 if no such k exists.
%C A240663 The least k, if it exists, such that prime(n) divides 8^k + 1.
%H A240663 T. D. Noe, <a href="/A240663/b240663.txt">Table of n, a(n) for n = 1..1000</a>
%F A240663 a(n) = A211244(n)/2 if A211244(n) is even, otherwise 0.
%t A240663 Table[p = Prime[n]; s = Select[Range[p/2], PowerMod[8, #, p] == p - 1 &, 1]; If[s == {}, 0, s[[1]]], {n, 100}]
%Y A240663 Cf. A211244 (order of 8 mod prime(n)).
%K A240663 nonn
%O A240663 1,3
%A A240663 _T. D. Noe_, Apr 14 2014