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 A300080 #13 Oct 12 2021 08:00:08
%S A300080 6,10,14,15,18,20,22,26,30,34,35,38,39,40,45,46,48,50,51,52,54,55,58,
%T A300080 60,62,68,70,74,75,78,82,85,86,87,90,94,95,96,98,100,102,104,105,106,
%U A300080 110,111,112,115,116,118,119,120,122,123,134,135,136,140,142,143,144,146,148,150,153,155,156,158,159,160,162,164,165,166
%N A300080 Numbers k that are not prime powers, and have exactly phi(phi(k)) residues modulo k of the maximum order.
%C A300080 Numbers k with at least two distinct prime factors (A024619) such that A111725(k) = A010554(k).
%H A300080 Amiram Eldar, <a href="/A300080/b300080.txt">Table of n, a(n) for n = 1..10000</a>
%t A300080 q[n_] := Count[(t = Table[MultiplicativeOrder[k, n], {k, Select[Range[n], CoprimeQ[n, #] &]}]), Max[t]] == EulerPhi[EulerPhi[n]]; Select[Range[200], PrimeNu[#] > 1 && q[#] &] (* _Amiram Eldar_, Oct 12 2021 *)
%Y A300080 Set difference of: A300064 and A000961, A300079 and A246547, A024619 and A300065.
%Y A300080 Cf. A000010, A002322, A010554, A111725.
%K A300080 nonn
%O A300080 1,1
%A A300080 _Max Alekseyev_, Feb 24 2018