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 A270034 #24 Jun 29 2019 01:39:51
%S A270034 0,0,0,0,0,0,0,9,0,0,0,0,0,0,0,0,9,10,11,12,13,14,15,16,17,9,19,10,21,
%T A270034 11,23,12,25,13,9,14,29,10,31,16,11,17,35,9,37,19,13,10,41,14,43,11,9,
%U A270034 23,47,12,49,10,17,13,53,9,11,14,19,29,59,10,61,31,9,9,9,9,9,9,9,9,9,9
%N A270034 a(n) is the smallest b for which the base-b representation of n contains at least one 8 (or 0 if no such base exists).
%C A270034 a(n) > 0 for n >= 17 since 18 is n written in base n-8.
%C A270034 The only perfect k-th powers (k >= 2) that can appear in this sequence are m^k with 2 <= m <= 8 and k a prime number.
%H A270034 Nathan Fox, <a href="/A270034/b270034.txt">Table of n, a(n) for n = 1..10000</a>
%t A270034 Table[SelectFirst[Range[9, 1200], DigitCount[n, #, 8] > 0 &], {n, 17, 120}] (* _Michael De Vlieger_, Mar 10 2016, Version 10 *)
%o A270034 (PARI) b(n) = if ((n<17) && (n!=8), 0, my(b=9); while(!vecsearch(Set(digits(n, b)), 8), b++); b); \\ _Michel Marcus_, Mar 10 2016
%Y A270034 Cf. A270027, A270028, A216194, A270029, A270030, A270031, A270032, A270033, A270035, A270044.
%K A270034 nonn,base
%O A270034 1,8
%A A270034 _Nathan Fox_, Mar 08 2016