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 A122182 #13 Jul 12 2015 20:35:36
%S A122182 1,3,6,10669,9,18,3763,1010,20,35,2951,42,50,27,36,49,56,110,697,578,
%T A122182 156,540923,70,287,104,147,4044,970,220,59378,119,345,66,3007,75,
%U A122182 1990362,184,190,100,115,81,162,470,406,812,6631,105,310,160,207,322
%N A122182 Least positive number k such that 2^k mod k = 2n, or 0 if no such k exists.
%t A122182 lpn[n_]:=Module[{k=1},While[PowerMod[2,k,k]!=2n,k++];k]; Array[lpn,60,0] (* _Harvey P. Dale_, Jul 23 2012 *)
%Y A122182 A bisection of A036236: a(n) = A036236(2n).
%Y A122182 Cf. A124977.
%K A122182 nonn
%O A122182 0,2
%A A122182 _N. J. A. Sloane_, May 11 2007, Jul 18 2008
%E A122182 New definition from _Benoit Jubin_, Jul 17 2008
%E A122182 More terms from _Max Alekseyev_, May 08 2009