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 A220491 #27 Jan 14 2021 21:16:05 %S A220491 0,10,102,1000,10000,102000,1000300,10000000,102000600,1000000000, %T A220491 10000108360,102000060480,1000006930000,10000063165960, %U A220491 102000042276960,1000000000000000,10000000141981840,102000006021375360,1000000081060819840,10000000000000000000 %N A220491 The smallest n-digit number whose last k digits are divisible by k for k = 1..n. %e A220491 There are ten one-digit numbers divisible by 1, and the smallest is 0, so a(1) = 0. %e A220491 For two-digit numbers, the ones digit must be divisible by 2 which gives 10 as the smallest to satisfy the requirement. So a(2) = 10. %Y A220491 Cf. A164836. %K A220491 nonn,base %O A220491 1,2 %A A220491 _Shyam Sunder Gupta_, Aug 07 2013 %E A220491 More terms from _Jinyuan Wang_, Mar 09 2020