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 A263016 #16 Aug 22 2017 20:18:18
%S A263016 20,24,40,48,60,80,96,120,140,156,160,180,192,240,260,272,280,312,320,
%T A263016 336,340,360,384,408,420,460,468,480,520,540,544,560,580,600,624,640,
%U A263016 672,680,696,720,740,768,780
%N A263016 Numbers n such that A263014(n) > 0.
%H A263016 Hans Havermann, <a href="/A263016/b263016.txt">Table of n, a(n) for n = 1..530</a>
%t A263016 sumin[n_, k_] := Mod[Sum[If[GCD[i, n] == 1, PowerMod[i, k, n], 0], {i, 1, n}], n]; Select[Range[100], sumin[#, #] > 0 &]
%Y A263016 Cf. A263014, A263015, A290287.
%K A263016 nonn
%O A263016 1,1
%A A263016 _José María Grau Ribas_, Oct 07 2015