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 A299158 #25 Feb 16 2025 08:33:53 %S A299158 2,3,5,6,7,20,27,45,91,160,240,243,343,384,792,896,2639,1163799 %N A299158 Numbers k such that k*(k+1) divides tau(k), where tau(k) = A000594(k) is Ramanujan's tau function. %C A299158 a(19) > 5*10^6. %C A299158 Numbers k such that A299165(k) = 0. %C A299158 Intersection of A063938 and A299157. %H A299158 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/TauFunction.html">Tau Function</a>. %t A299158 Select[Range[1000], Divisible[RamanujanTau[#], #*(#+1)] &] (* _Amiram Eldar_, Jan 10 2025 *) %o A299158 (PARI) isok(k) = !(ramanujantau(k) % (k*(k+1))); \\ _Amiram Eldar_, Jan 10 2025 %Y A299158 Cf. A000594, A063938, A299157, A299165. %K A299158 nonn,more %O A299158 1,1 %A A299158 _Seiichi Manyama_, Feb 04 2018