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 A038451 #14 Mar 11 2025 09:45:34
%S A038451 111111111,1011111111,1101111111,1110111111,1111011111,1111101111,
%T A038451 1111110111,1111111011,1111111101,1111111110,10011111111,10101111111,
%U A038451 10110111111,10111011111,10111101111,10111110111,10111111011
%N A038451 Sums of 9 distinct powers of 10.
%H A038451 Amiram Eldar, <a href="/A038451/b038451.txt">Table of n, a(n) for n = 1..10000</a>
%t A038451 Sort[Plus @@@ Subsets[10^Range[0, 10], {9}]] (* _Amiram Eldar_, Jul 12 2022 *)
%o A038451 (Python)
%o A038451 from itertools import islice
%o A038451 def A038451_gen(): # generator of terms
%o A038451 yield int(bin(n:=511)[2:])
%o A038451 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 A038451 A038451_list = list(islice(A038451_gen(),20)) # _Chai Wah Wu_, Mar 11 2025
%Y A038451 Cf. A011557.
%Y A038451 Cf. A038444, A038445, A038446, A038447, A038448, A038449, A038450, A038452, A038453, A038454.
%K A038451 nonn,easy
%O A038451 1,1
%A A038451 _Olivier Gérard_
%E A038451 Offset corrected by _Amiram Eldar_, Jul 12 2022