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 A351540 #12 Feb 16 2022 17:05:54
%S A351540 30,51,66,96,102,120,138,159,165,174,204,210,213,246,255,264,267,282,
%T A351540 294,306,318,321,330,345,354,357,364,390,408,426,435,462,477,480,498,
%U A351540 510,534,537,552,561,570,591,606,615,636,642,660,663,672,678,679,690,696,699,705,714,735,745,750,753,759,760,765,786
%N A351540 Numbers k that have an odd prime factor p such that p^(1+valuation(k,p)) divides sigma(k).
%H A351540 <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a>
%e A351540 30 = 2 * 3 * 5 is present as sigma(30) = 72 = 2^3 * 3^2, and thus there is at least one odd prime factor (in this case 3) such that a higher power of the same prime divides the sum of divisors of the same number.
%t A351540 Select[Range[2, 800], Function[{k, s}, AnyTrue[DeleteCases[FactorInteger[k][[All, 1]], 2], Mod[s, #^(1 + IntegerExponent[k, #])] == 0 &]] @@ {#, DivisorSigma[1, #]} &] (* _Michael De Vlieger_, Feb 16 2022 *)
%o A351540 (PARI)
%o A351540 A351539(n) = { my(f=factor(n),s=sigma(n)); sum(k=1,#f~,(f[k,1]%2)&&(0==(s%(f[k,1]^(1+f[k,2]))))); };
%o A351540 isA351540(n) = (A351539(n)>0);
%Y A351540 Positions of nonzero terms in A351539.
%Y A351540 Cf. A000203, A351541 (subsequence).
%Y A351540 Probably subsequence: A007691 \ (A323653 U A336702).
%Y A351540 Cf. also A336353.
%K A351540 nonn
%O A351540 1,1
%A A351540 _Antti Karttunen_, Feb 16 2022