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 A031882 #32 Jul 30 2019 05:31:56 %S A031882 1,3,7,9,33,99,111,777,9999,33333,55555,111111,777777,7777777,55555555 %N A031882 Repdigital lucky numbers. %C A031882 a(16) > 10^8. - _Robert G. Wilson v_, May 12 2006 %C A031882 a(16) > 10^9. - _Luke March_, Jul 22 2014 %t A031882 lst=Range[1, 10^7, 2]; i = 2; While[lst[[i]]<=Length[lst], del=Partition[Range[lst[[i]], Length[lst], lst[[i]]], 1]; lst=Delete[lst, del]; i++ ]; lst=Select[lst, (Length[Union[IntegerDigits[ # ]]]==1)&] (* _Robert G. Wilson v_, May 12 2006 *) %Y A031882 Intersection of A000959 and A010785. %Y A031882 Subset of A309406. %K A031882 base,nonn,more %O A031882 1,2 %A A031882 _Patrick De Geest_ %E A031882 Two more terms from Vit Planocka (planocka(AT)mistral.cz), Feb 01 2003 %E A031882 a(15) from _Robert G. Wilson v_, May 12 2006