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 A072874 #15 Jul 23 2024 20:41:13
%S A072874 1,2,4,8,16,24,28,32,36,47,53,56,64,72,80,94,103,106,128,163,192,199,
%T A072874 206,256,257,269,311,326,336,384,397,398,401,419,421,456,499,512,514,
%U A072874 536,538,587,599,617,622,683,700,757,768,773,794,802,838,842,863,883,907
%N A072874 Numbers k such that A000213(k) == 1 (mod k).
%C A072874 Includes A000079. - _Robert Israel_, Jul 23 2024
%H A072874 Amiram Eldar, <a href="/A072874/b072874.txt">Table of n, a(n) for n = 1..10000</a>
%t A072874 m = 1000; t = LinearRecurrence[{1, 1, 1}, {1, 1, 3}, m]; Position[(t - 1)/Range[m], _?IntegerQ] // Flatten (* _Amiram Eldar_, May 05 2022 *)
%Y A072874 Cf. A000213, A023173.
%K A072874 easy,nonn
%O A072874 1,2
%A A072874 _Benoit Cloitre_, Jul 28 2002
%E A072874 a(1) = 1 inserted by _Amiram Eldar_, May 05 2022