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 A212284 #12 Apr 28 2019 18:31:04 %S A212284 20,21,12,40,50,21,70,153,10,190,108,40,126,135,50,153,162,20,180,190, %T A212284 70,207,216,80,234,243,30,261,270,190,290,594,102,315,324,40,342,351, %U A212284 120,370,380,130,792,405,50,423,432,150,450,460,160,480,490,60,504 %N A212284 First a(n) > 1 whose sum of digits is the same in base 10 as in base n. %C A212284 There might exist an n for which there is no solution, in which case a(n) would be set to 0 by convention; however, no such case was found so far. Problem: does it exist? %H A212284 Stanislav Sykora, <a href="/A212284/b212284.txt">Table of n, a(n) for n = 2..10000</a> %e A212284 a(12)=108 because 108 is the first number > 1 such that when written in base 10 and in base 12 (i.e., 90), the sum of the expansion digits is the same, namely 9. %Y A212284 Cf. A037308. %K A212284 nonn,easy,base %O A212284 2,1 %A A212284 _Stanislav Sykora_, May 08 2012