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 A038454 #22 Mar 11 2025 09:44:46
%S A038454 111111111111,1011111111111,1101111111111,1110111111111,1111011111111,
%T A038454 1111101111111,1111110111111,1111111011111,1111111101111,
%U A038454 1111111110111,1111111111011,1111111111101,1111111111110,10011111111111,10101111111111,10110111111111,10111011111111,10111101111111
%N A038454 Sums of 12 distinct powers of 10.
%H A038454 Robert Israel, <a href="/A038454/b038454.txt">Table of n, a(n) for n = 1..10000</a>
%F A038454 a(binomial(N,12)+k) = 10^N + A038453(k) for 1 <= k <= binomial(N,11). - _Robert Israel_, Feb 28 2016
%p A038454 N:= 14: # to get all terms of at most N digits
%p A038454 sort(map(t -> (10^N-1)/9 - add(10^j, j=t),
%p A038454 combinat:-choose([$0..N-1],N-12))); # _Robert Israel_, Feb 28 2016
%t A038454 Sort[Plus @@@ Subsets[10^Range[0, 12], {12}]] (* _Amiram Eldar_, Jul 12 2022 *)
%o A038454 (Python)
%o A038454 from itertools import islice
%o A038454 def A038454_gen(): # generator of terms
%o A038454 yield int(bin(n:=4095)[2:])
%o A038454 while True: yield int(bin((n:=n^((a:=-n&n+1)|(a>>1)) if n&1 else ((n&~(b:=n+(a:=n&-n)))>>a.bit_length())^b))[2:])
%o A038454 A038454_list = list(islice(A038454_gen(),20)) # _Chai Wah Wu_, Mar 11 2025
%Y A038454 Cf. A011557.
%Y A038454 Cf. A038444, A038445, A038446, A038447, A038448, A038449, A038450, A038451, A038452, A038453.
%K A038454 nonn,easy
%O A038454 1,1
%A A038454 _Olivier Gérard_
%E A038454 Offset changed to 1 by _Ivan Neretin_, Feb 28 2016