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 A038463 #16 Mar 11 2025 03:49:24
%S A038463 4095,6143,7167,7679,7935,8063,8127,8159,8175,8183,8187,8189,8190,
%T A038463 10239,11263,11775,12031,12159,12223,12255,12271,12279,12283,12285,
%U A038463 12286,13311,13823,14079,14207,14271,14303,14319,14327,14331,14333
%N A038463 Sums of 12 distinct powers of 2.
%H A038463 Ivan Neretin, <a href="/A038463/b038463.txt">Table of n, a(n) for n = 1..10000</a>
%H A038463 Robert Baillie, <a href="http://arxiv.org/abs/0806.4410">Summing the curious series of Kempner and Irwin</a>, arXiv:0806.4410 [math.CA], 2008-2015. See p. 18 for Mathematica code irwinSums.m.
%F A038463 Sum_{n>=1} 1/a(n) = 1.386296350824871649202152615241744383837323713474767661902780220440945591424... (calculated using Baillie's irwinSums.m, see Links). - _Amiram Eldar_, Feb 14 2022
%t A038463 Select[Range[15000], DigitCount[#, 2, 1] == 12 &] (* _Amiram Eldar_, Feb 14 2022 *)
%o A038463 (Python)
%o A038463 from itertools import islice
%o A038463 def A038463_gen(): # generator of terms
%o A038463 yield (n:=4095)
%o A038463 while True: yield (n:=n^((a:=-n&n+1)|(a>>1)) if n&1 else ((n&~(b:=n+(a:=n&-n)))>>a.bit_length())^b)
%o A038463 A038463_list = list(islice(A038463_gen(),20)) # _Chai Wah Wu_, Mar 10 2025
%Y A038463 Base 2 interpretation of A038454.
%Y A038463 Cf. A000079, A018900, A014311, A014312, A014313, A023688, A023689, A023690, A023691, A038461, A038462 (Hamming weight = 1, 2, ..., 11).
%K A038463 nonn,base,easy
%O A038463 1,1
%A A038463 _Olivier Gérard_
%E A038463 Offset changed to 1 by _Ivan Neretin_, Feb 28 2016