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 A334839 #8 May 14 2020 06:12:53 %S A334839 6,18,42,162,486,1458,4422,6162,14406,19182,22650,26406,39366,77658, %T A334839 143262,412806,527802,564898,843642,981090,1514130,2023506,2453922, %U A334839 3050262,3946182,4042110,4590306,5010882,6931390,7003962,7067622,7195806,7455630,9349410,10696170,11092230 %N A334839 Totients congruent to 2 mod 4 and that have multiplicity 4. %H A334839 Max Alekseyev, <a href="http://home.gwu.edu/~maxal/gpscripts/">PARI scripts for various problems</a> (see invphi.gp there). %H A334839 Andre Contiero, and Davi Lima, <a href="https://arxiv.org/abs/1803.01396">On the distribution of totients 2 mod. 4</a>, arXiv:1803.01396 [math.NT], 4 Mar 2018. %H A334839 André Contiero, and Davi Lima, <a href="https://arxiv.org/abs/2005.05475">2-Adic Stratification of Totients</a>, arXiv:2005.05475 [math.NT], 2020. %e A334839 6 is a term since there are exactly 4 integers x for which phi(x)=6, namely 7, 9, 14, and 18. %o A334839 (PARI) isok(m) = ((m%4)==2) && istotient(m) && (#invphi(m)==4); %Y A334839 Cf. A000010, A002202, A016825, A309502. %K A334839 nonn %O A334839 1,1 %A A334839 _Michel Marcus_, May 13 2020