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 A078246 #14 Dec 27 2019 19:09:16
%S A078246 7,70,777,700,70,7770,7,7000,777777777,70,77,77700,7007,70,7770,70000,
%T A078246 77707,7777777770,77007,700,777,770,770707,777000,700,70070,
%U A078246 7707777777,700,7707707,7770,777077,700000,777777,777070,70,77777777700,777,770070
%N A078246 Smallest multiple of n using only digits 0 and 7.
%C A078246 a(n) = min{A204094(k): k > 0 and A204094(k) mod n = 0}. [_Reinhard Zumkeller_, Jan 10 2012]
%H A078246 Reinhard Zumkeller, <a href="/A078246/b078246.txt">Table of n, a(n) for n = 1..998</a>
%t A078246 With[{c=Rest[FromDigits/@Tuples[{0,7},11]]},Table[SelectFirst[c, Divisible[ #,n]&],{n,40}]] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Dec 27 2019 *)
%o A078246 (Haskell)
%o A078246 a078246 n = head [x | x <- tail a204094_list, mod x n == 0]
%o A078246 -- _Reinhard Zumkeller_, Jan 10 2012
%Y A078246 Cf. A004290, A078241-A078248, A079339, A096681-A096688.
%K A078246 base,nonn
%O A078246 1,1
%A A078246 _Amarnath Murthy_, Nov 23 2002
%E A078246 More terms from _Ray Chandler_, Jul 12 2004