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 A317295 #28 Jul 23 2023 06:08:36
%S A317295 15,23,27,29,30,39,43,45,46,51,53,54,57,58,60,63,71,75,77,78,83,85,86,
%T A317295 89,90,92,95,99,101,102,105,106,108,111,113,114,116,119,120,123,125,
%U A317295 126,135,139,141,142,147,149,150,153,154,156,159,163,165,166,169,170,172,175,177,178,180,183,184,187,189,190
%N A317295 Numbers with a composite number of 1's in their binary expansion.
%C A317295 By definition no power of 2 is in the sequence.
%H A317295 Amiram Eldar, <a href="/A317295/b317295.txt">Table of n, a(n) for n = 1..10000</a>
%e A317295 23 is in the sequence because the binary expansion of 23 is 10111 and 10111 has four 1's, and 4 is a composite number (A002808).
%t A317295 Select[Range[200], CompositeQ[DigitCount[#, 2, 1]] &] (* _Amiram Eldar_, Jul 23 2023 *)
%o A317295 (PARI) isok(n) = my(w = hammingweight(n)); (w != 1) && !isprime(w); \\ _Michel Marcus_, Aug 15 2018
%o A317295 (Python) from sympy import isprime; isok = lambda n: n & (n-1) and not isprime(bin(n).count('1')) # _David Radcliffe_, Aug 15 2018
%Y A317295 Complement of A317294.
%Y A317295 Cf. A000069, A000120, A001969, A002808, A014312, A052294, A084345.
%K A317295 nonn,base,easy
%O A317295 1,1
%A A317295 _Omar E. Pol_, Aug 10 2018