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 A176772 #9 Apr 04 2024 07:52:41 %S A176772 4826809,1,2197,13,4826809,28561,169,2197,28561,169,10604499373, %T A176772 51185893014090757,371293,13,51185893014090757,815730721,169,62748517, %U A176772 137858491849,2197,1461920290375446110677,2197,23298085122481 %N A176772 Smallest power of 13 whose decimal expansion contains n. %C A176772 This is to 13 as A176763 is to 3 and as A030001 is to 2. %H A176772 Paolo Xausa, <a href="/A176772/b176772.txt">Table of n, a(n) for n = 0..10000</a> %F A176772 a(n) = MIN{A001022(i) such that n in decimal representation is a substring of A001022(i)}. %e A176772 a(1) = 1 because 13^0 = 1 has "1" as a substring (not a proper substring, though). %e A176772 a(2) = 2197 because 13^3 = 2197 has "2" as a substring. %e A176772 a(3) = 13 because 13^1 = 13 has "3" as a substring. %t A176772 A176772[n_] := Block[{k = -1}, While[StringFreeQ[IntegerString[13^++k], IntegerString[n]]]; 13^k]; Array[A176772, 50, 0] (* _Paolo Xausa_, Apr 04 2024 *) %Y A176772 Cf. A001022, A030001, A176763, A176764-A176773. %K A176772 base,easy,nonn %O A176772 0,1 %A A176772 _Jonathan Vos Post_, Apr 25 2010 %E A176772 More terms from _Sean A. Irvine_ and _Jon E. Schoenfield_, May 05 2010 %E A176772 a(0) prepended by _Paolo Xausa_, Apr 04 2024