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 A371082 #13 Aug 27 2025 18:21:39
%S A371082 153,477,637,909,1017,1233,1557,2097,3577,4753,9457,10693,10933,12393,
%T A371082 13357,14013,15337,17629,20817,21097,21217,22021,26353,29449,30037,
%U A371082 30717,31117,31149,31797,32013,32229,32337,32481,32977,35557,35917,38637,38725,41797,42237,50029,53557,56497,56677,56953,58621,59437,60309
%N A371082 Composite numbers for which A324644(n)/A324198(n) = 2 and sigma(n) == 2 (mod 4).
%H A371082 Antti Karttunen, <a href="/A371082/b371082.txt">Table of n, a(n) for n = 1..20000</a>
%H A371082 <a href="/index/O#opnseqs">Index entries for sequences where odd perfect numbers must occur, if they exist at all</a>
%H A371082 <a href="/index/Pri#primorialbase">Index entries for sequences related to primorial base</a>
%H A371082 <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a>
%t A371082 f[x_] := Block[{m, i, n = x, p}, m = i = 1; While[n > 0, p = Prime[i]; m *= p^Mod[n, p]; n = Quotient[n, p]; i++]; m]; Select[Select[Range[2^16], CompositeQ], GCD[#2, #3]/GCD[#1, #3] == Mod[#2, 4] == 2 & @@ {#, DivisorSigma[1, #], f[#]} &] (* _Michael De Vlieger_, Mar 10 2024 *)
%o A371082 (PARI)
%o A371082 A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
%o A371082 isA371082(n) = if(isprime(n) || (2!=(sigma(n)%4)), 0, my(u=A276086(n)); (gcd(sigma(n),u)==2*gcd(n,u)));
%Y A371082 Intersection of A191218 and A364286.
%Y A371082 Apparently also the intersection of A228058 and A364286.
%Y A371082 Cf. A000203, A276086, A351458.
%K A371082 nonn,changed
%O A371082 1,1
%A A371082 _Antti Karttunen_, Mar 10 2024