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 A069523 #8 Aug 06 2019 06:15:16 %S A069523 4,4,0,4,40,0,112,40,0,40,22,0,13,112,0,112,1003,0,1102,40,0,22,1012, %T A069523 0,400,130,0,112,1102,0,31,1120,0,10030,1120,0,0,1102,0,40,0,0,301, %U A069523 220,0,1012,300001,0,120001,400,0,1300,1001011,0,220,112,0,1102,1003,0 %N A069523 Smallest multiple of n with digit sum = 4, or 0 if no such number exists, e.g. a(3k)= 0. %C A069523 a(3k)=a(37k)=a(41k)=0. - _Ray Chandler_, Jul 30 2003 %F A069523 a(n) = n*A088393(n). - _R. J. Mathar_, Aug 06 2019 %Y A069523 Cf. A052218, A069521, A069522. %K A069523 base,nonn %O A069523 1,1 %A A069523 _Amarnath Murthy_, Apr 01 2002 %E A069523 More terms from _Ray Chandler_, Jul 30 2003