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 A076234 #18 May 09 2024 02:54:13 %S A076234 1,6,120,672,30240,32760,33550336,459818240,1379454720,8589869056, %T A076234 31998395520,51001180160,137438691328,153003540480,30823866178560, %U A076234 796928461056000,6088728021160320,212517062615531520,2305843008139952128,69357059049509038080,143573364313605309726720 %N A076234 Numbers k such that sigma(k)/k, sigma_3(k)/k, sigma_5(k)/k and sigma_7(k)/k are all integers. %H A076234 Amiram Eldar, <a href="/A076234/b076234.txt">Table of n, a(n) for n = 1..55</a> %o A076234 (PARI) isok(n) = !(sigma(n) % n) && !(sigma(n, 3) % n) && !(sigma(n, 5) % n) && !(sigma(n, 7) % n); \\ _Michel Marcus_, Dec 26 2013 %Y A076234 Cf. A000203, A001158, A001160, A013955. %Y A076234 Cf. A007691, A046763, A055709, A076231, A076233. %Y A076234 Cf. A066289 (k divides sigma_m(k) for all odd m). %K A076234 nonn %O A076234 1,2 %A A076234 _Labos Elemer_, Oct 04 2002 %E A076234 a(13)-a(18) from _Donovan Johnson_, May 08 2010 %E A076234 a(19)-a(21) from _Amiram Eldar_, May 09 2024