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 A260508 #16 May 09 2024 02:52:46 %S A260508 6,28,120,496,672,8128,30240,33550336,8589869056,137438691328, %T A260508 2305843008139952128,2658455991569831744654692615953842176, %U A260508 191561942608236107294793378084303638130997321548169216,13164036458569648337239753460458722910223472318386943117783728128 %N A260508 Numbers k such that A000203(k) = k*A001221(k). %C A260508 a(n) is in A000396 iff A001221(a(n)) == 2, i.e., if a(n) is in A007774. %C A260508 a(11) > 2.5*10^12. - _Giovanni Resta_, Jul 28 2015 %H A260508 Amiram Eldar, <a href="/A260508/b260508.txt">Table of n, a(n) for n = 1..15</a> %o A260508 (PARI) is(n) = sigma(n)==n*omega(n) %Y A260508 Subsequence of A007691. %Y A260508 Cf. A000203, A000396, A001221, A007774. %K A260508 nonn %O A260508 1,1 %A A260508 _Felix Fröhlich_, Jul 27 2015 %E A260508 a(9)-a(10) from _Giovanni Resta_, Jul 28 2015 %E A260508 a(11)-a(14) from _Amiram Eldar_, May 09 2024