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 A031461 #16 Aug 03 2023 03:44:05
%S A031461 1,2,5,6,9,10,12,19,21,22,25,26,28,35,37,38,41,42,44,49,50,52,56,71,
%T A031461 75,77,78,83,85,86,89,90,92,99,101,102,105,106,108,113,114,116,120,
%U A031461 135,139,141,142,147,149,150,153,154,156,163,165
%N A031461 Numbers whose base-4 representation has the same number of 0's as 3's.
%C A031461 Union of A031443 and A031448, i.e., numbers k in binary where the difference between numbers of 1's and 0's [A000120(k) - A023416(k) = -A037861(k)] is 1 or 0. - _Henry Bottomley_, Mar 02 2001
%H A031461 Amiram Eldar, <a href="/A031461/b031461.txt">Table of n, a(n) for n = 1..10000</a>
%t A031461 Select[Range[165], Equal @@ DigitCount[#, 4, {0, 3}] &] (* _Amiram Eldar_, Aug 03 2023 *)
%Y A031461 Cf. A000120, A007090, A023416, A031443, A031448, A037861.
%K A031461 nonn,base
%O A031461 1,2
%A A031461 _Clark Kimberling_