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 A364131 #34 Jul 15 2023 21:59:55
%S A364131 1,2,4,9,16,25,64,81,289,324,400,484,729,1681,2401,3481,4096,5041,
%T A364131 7921,10201,15625,17161,27889,28561,29929,39204,65536,83521,85849,
%U A364131 146689,262144,279841,458329,491401,531441,552049,579121,597529,683929,703921,707281,734449,829921,1190281,1203409,1352569,1394761,1423249,1481089
%N A364131 Numbers k for which A348717(k) is a multiple of A348717(sigma(k)).
%C A364131 Conjecture: All terms apart from a(2) = 2 are squares.
%H A364131 <a href="/index/Pri#prime_indices">Index entries for sequences computed from indices in prime factorization</a>
%H A364131 <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a>
%o A364131 (PARI)
%o A364131 A348717(n) = { my(f=factor(n)); if(#f~>0, my(pi1=primepi(f[1, 1])); for(k=1, #f~, f[k, 1] = prime(primepi(f[k, 1])-pi1+1))); factorback(f); }; \\ From A348717
%o A364131 isA364131(n) = !(A348717(n)%A348717(sigma(n)));
%Y A364131 Cf. A000203, A008848, A023194 (subsequence), A348717, A350072.
%K A364131 nonn
%O A364131 1,2
%A A364131 _Antti Karttunen_, Jul 11 2023