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 A297001 #22 Feb 16 2025 08:33:52
%S A297001 3,9,12,18,21,27,36,40,42,48,54,72,81,84,108,120,135,144,162,168,189,
%T A297001 192,216,243,270,280,324,336,360,378,432,448,486,540,576,640,648,672,
%U A297001 729,756,768,828,840,864,945,972,1080,1152,1296,1344,1458,1512,1701,1728,1890
%N A297001 Numbers k such that A296992(k) = 2.
%H A297001 Amiram Eldar, <a href="/A297001/b297001.txt">Table of n, a(n) for n = 1..250</a>
%H A297001 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/TauFunction.html">Tau Function</a>.
%t A297001 1 + Position[Table[-1 + SelectFirst[Range[0, 5], !Divisible[RamanujanTau@ n, n^#] &], {n, 2, 2000}], 2][[All, 1]] (* _Michael De Vlieger_, Dec 23 2017 *)
%o A297001 (PARI) isok(k) = if(k == 1, 0, valuation(ramanujantau(k), k) == 2); \\ _Amiram Eldar_, Jan 09 2025
%Y A297001 Cf. A000594, A296991, A296992, A297000.
%K A297001 nonn
%O A297001 1,1
%A A297001 _Seiichi Manyama_ and _Robert G. Wilson v_, Dec 23 2017