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 A345387 #9 Jun 18 2021 12:19:19
%S A345387 531,541,1053,1054,2571,3051,3061,3071,3105,3106,3107,3157,3551,3561,
%T A345387 3571,3581,3591,4051,4061,4071,4081,4091,4105,4106,4107,4108,4109,
%U A345387 4155,4156,4157,4158,4159,4551,4561,4571,4581,4591,5031,5041,5103,5104,5128,5129,5153,5154
%N A345387 Numbers k such that k, 2k, 3k, 4k all contain digit 1.
%e A345387 The first four multiples of 531 are 531, 1062, 1593, and 2124. All of them contain digit 1.
%t A345387 Select[Range[10000], Length[ Position[IntegerDigits[#], 1]] > 0 && Length[ Position[IntegerDigits[2 #], 1]] > 0 && Length[ Position[IntegerDigits[3 #], 1]] > 0 && Length[ Position[IntegerDigits[4 #], 1]] > 0 &]
%o A345387 (Python)
%o A345387 def ok(n): return all('1' in str(k*n) for k in [1, 2, 3, 4])
%o A345387 print(list(filter(ok, range(5155)))) # _Michael S. Branicky_, Jun 17 2021
%Y A345387 Cf. A011531.
%K A345387 nonn,base
%O A345387 1,1
%A A345387 _Tanya Khovanova_, Jun 17 2021