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 A124476 #13 Feb 13 2024 11:41:27
%S A124476 67,76,6777,76,7776,6776,776,6777,6677,7776,676,6776,7776,6766,7776,
%T A124476 76,67767,6776,667,7776,676,6777,6776,667,67766,7776,66777777,6766,
%U A124476 7776,666777,76,77766,7667,76776,676777,6776,67666,667776,7776,67767,67677
%N A124476 Smallest multiple of A047201(n) (i.e., numbers not divisible by 5) with only digits 6 and 7.
%H A124476 Nick Hobson, <a href="https://web.archive.org/web/20160802192115/http://www.qbyte.org/puzzles/p080s.html">Solution to Puzzle 80:"Sixes and sevens" (generalization of)</a>
%t A124476 f[n_] := Block[{k = n},While[Union @ IntegerDigits[k] != {6, 7}, k += n];k];f /@ Select[Range[52], Mod[ #, 5] > 0 &] (* _Ray Chandler_, Dec 18 2006 *)
%K A124476 nonn,base
%O A124476 1,1
%A A124476 _Lekraj Beedassy_, Dec 17 2006
%E A124476 Corrected and extended by _Ray Chandler_, Dec 18 2006