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 A078244 #14 Aug 14 2021 11:33:50
%S A078244 5,50,555,500,5,5550,5005,5000,555555555,50,55,55500,5005,50050,555,
%T A078244 50000,55505,5555555550,55005,500,50505,550,550505,555000,50,50050,
%U A078244 5505555555,500500,5505505,5550,555055,500000,555555,555050,5005
%N A078244 Smallest multiple of n using only digits 0 and 5.
%C A078244 a(n) = min{A169964(k): k > 1 and A169964(k) mod n = 0}. [_Reinhard Zumkeller_, Jan 10 2012]
%H A078244 Reinhard Zumkeller, <a href="/A078244/b078244.txt">Table of n, a(n) for n = 1..998</a>
%t A078244 Module[{mlts=Rest[FromDigits/@Tuples[{0,5},12]]},Table[ SelectFirst[ mlts,Divisible[ #,n]&],{n,40}]] (* _Harvey P. Dale_, Aug 14 2021 *)
%o A078244 (Haskell)
%o A078244 a078244 n = head [x | x <- tail a169964_list, mod x n == 0]
%o A078244 -- _Reinhard Zumkeller_, Jan 10 2012
%Y A078244 Cf. A004290, A078241-A078248, A079339, A096681-A096688.
%K A078244 base,nonn
%O A078244 1,1
%A A078244 _Amarnath Murthy_, Nov 23 2002
%E A078244 More terms from _Ray Chandler_, Jul 12 2004