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 A345054 #7 Jun 07 2021 06:51:17 %S A345054 27,243,1377,2187,3125,19683,28125,55233,68445,177147,195625,203125, %T A345054 239805,253125,453125,823543,907137,1323297,1378125,1464561,1594323, %U A345054 1953125,2278125,3341637,3572829,5255361,5877117,9034497,9819837,11701053,14348907,17453125,19460393,20503125,22209633,26010621,30074733,44910045 %N A345054 Odd numbers k such that A173557(k) divides nonzero A051709(k). %C A345054 Question: Are there any common terms with A345051? %H A345054 <a href="/index/O#opnseqs">Index entries for sequences where odd perfect numbers must occur, if they exist at all</a> %o A345054 (PARI) %o A345054 A051709(n) = ((sigma(n) + eulerphi(n)) - (2*n)); %o A345054 A173557(n) = factorback(apply(p -> p-1, factor(n)[, 1])); %o A345054 isA345054(n) = if(!(n%2),0,my(u=A051709(n)); ((u>0)&&(0==(u%A173557(n))))); %Y A345054 Odd terms in A344994. %Y A345054 Cf. A051709, A173557, A345051. %K A345054 nonn %O A345054 1,1 %A A345054 _Antti Karttunen_, Jun 06 2021