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 A067562 #20 Jun 13 2021 09:02:04 %S A067562 1,3,15,63,75,105,165,195,231,255,285,315,495,525,585,735,825,945,975, %T A067562 1155,1275,1365,1485,1575,1755,1785,1815,1995,2145,2205,2415,2475, %U A067562 2535,2625,2805,2835,2925,3003,3045,3135,3255,3315,3465,3675,3705,3795,3885,3927 %N A067562 Odd values of k such that phi(k)! divides phi(k!) where phi(k) = A000010(k). %C A067562 a(n) == 0 (mod 3) for any n > 1. %C A067562 k cannot be divisible by 5 for k = 1, 3, 63, 231, 3003, 3927, 4389, 4641, 5187, 5313, 9009, 11781, 13167, 13923, 15561, 15939, 21021, 27027, 27489, 30723, ... - _Jinyuan Wang_, Apr 05 2020 %o A067562 (PARI) is(k) = (k%6==3 && eulerphi(k!)%eulerphi(k)!==0) || k==1; \\ _Jinyuan Wang_, Apr 05 2020 %Y A067562 Cf. A000010, A048855. %K A067562 nonn %O A067562 1,2 %A A067562 _Benoit Cloitre_, Jan 29 2002; corrected Jun 03 2003 %E A067562 More terms from _Jinyuan Wang_, Apr 05 2020