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 A324726 #21 Jan 08 2025 17:02:49
%S A324726 3,6,7,14,15,21,22,28,31,46,55,57,62,63,86,92,93,94,105,110,111,124,
%T A324726 127,154,170,171,188,189,190,201,213,215,217,231,237,248,249,250,253,
%U A324726 254,255,310,315,316,351,357,363,369,374,376,381,382,393,430,434,447,465,469,473,483,489,494,496,497,501,506,508,511,602
%N A324726 Numbers k such that 2*k is equal to 2*k OR sigma(k), where OR is bitwise-or, A003986, and sigma is the sum of divisors function.
%C A324726 Intersection with A324652 gives A000396.
%C A324726 These are all nonabundant (in A263837) because of the "monotonic property" of bitwise-or. - _Antti Karttunen_, Jan 08 2025
%H A324726 Antti Karttunen, <a href="/A324726/b324726.txt">Table of n, a(n) for n = 1..20000</a>
%H A324726 <a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a>
%H A324726 <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a>
%F A324726 {k such that 2*k = A318466(k)}.
%t A324726 Select[Range[1000], 2*# == BitOr[2*#, DivisorSigma[1, #]] &] (* _Paolo Xausa_, Mar 11 2024 *)
%o A324726 (PARI) for(n=1, oo, if(((2*n)==bitor(2*n, sigma(n))), print1(n, ", ")));
%Y A324726 Cf. A000396, A003986, A318466, A324652, A324723, A324727 (the odd terms).
%Y A324726 Subsequence of A263837.
%K A324726 nonn,look
%O A324726 1,1
%A A324726 _Antti Karttunen_, Mar 15 2019