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 A347394 #8 Sep 17 2021 16:17:08 %S A347394 21,26,30,32,33,36,37,40,42,44,48,49,50,54,60,65,75,80,84,90,91,112, %T A347394 120,125,126,153,162,175,176,198,208,220,231,252,272,275,304,325,343, %U A347394 368,400,425,475,546,575,725,765,775,11132,12750,13167,31262,46893,55660,63825,78155,93500,171171,191301,406406,483771,609609 %N A347394 Positions of 4's in A347381. %C A347394 Question: Why the sudden rarification of terms after a(48) = 775? %H A347394 <a href="/index/Pri#prime_indices">Index entries for sequences computed from indices in prime factorization</a> %H A347394 <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a> %Y A347394 Cf. A347381. %Y A347394 Cf. also A336702, A347391, A347392, A347393. %K A347394 nonn %O A347394 1,1 %A A347394 _Antti Karttunen_, Aug 31 2021