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 A387165 #13 Aug 28 2025 17:26:00
%S A387165 38745,77805,78435,118755,141075,157815,210735,237195,241605,294975,
%T A387165 300105,323505,364455,371925,390195,409185,455715,475335,499905,
%U A387165 567945,607635,660825,701415,733005,766395,806085,809325,872235,885465,891135,937755,964845,978705,1101555,1150065,1201095,1229445,1265355,1293705
%N A387165 Nondeficient numbers k for which A324644(k)/A324198(k) = 2.
%C A387165 First three nonmultiples of 5 occur at a(138), a(276), a(356) = 4446981, 8909901, 11234223. (Cf. A005231, A064001).
%H A387165 Antti Karttunen, <a href="/A387165/b387165.txt">Table of n, a(n) for n = 1..10000</a>
%H A387165 <a href="/index/Pri#primorialbase">Index entries for sequences related to primorial base</a>
%H A387165 <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a>
%H A387165 <a href="/index/O#opnseqs">Index entries for sequences where odd perfect numbers must occur, if they exist at all</a>
%F A387165 {k | sigma(k) >= 2*k, A324644(k) = 2*A324198(k)}.
%o A387165 (PARI)
%o A387165 A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
%o A387165 is_A387165(n) = if(sigma(n)<2*n, 0, my(u=A276086(n)); (gcd(sigma(n),u)==2*gcd(n,u)));
%Y A387165 Intersection of A023196 and A364286.
%Y A387165 Cf. A000203, A276086.
%Y A387165 Cf. also A371082, A386422, A387163 and A047802, A064001, A115414.
%K A387165 nonn,new
%O A387165 1,1
%A A387165 _Antti Karttunen_, Aug 28 2025