cp's OEIS Frontend

A176763 Smallest power of 3 whose decimal expansion contains n.

%I A176763 #18 Apr 03 2024 10:06:35
%S A176763 59049,1,27,3,243,6561,6561,27,81,9,10460353203,1162261467,129140163,
%T A176763 31381059609,177147,1594323,129140163,177147,2187,19683,387420489,
%U A176763 2187,1162261467,1594323,243,2541865828329,1162261467,27,282429536481,729,43046721,531441,1594323
%N A176763 Smallest power of 3 whose decimal expansion contains n.
%C A176763 This is to 3 as A030001 is to 2.
%H A176763 Paolo Xausa, <a href="/A176763/b176763.txt">Table of n, a(n) for n = 0..10000</a>
%F A176763 a(n) = MIN{A000244(i) such that n in decimal representation is a substring of A000244(i)}.
%e A176763 a(1) = 1 because 3^0 = 1 has "1" as a substring (not a proper substring, though).
%e A176763 a(2) = 27 because 3^3 = 27 has "2" as a substring.
%e A176763 a(10) = 10460353203 because 3^21 = 10460353203 is the smallest power of 3 whose decimal expansion contains "10" (in this case, "10" happens to be the left-hand or initial digits, but that is not generally true).
%t A176763 A176763[n_] := Block[{k = -1}, While[StringFreeQ[IntegerString[3^++k], IntegerString[n]]]; 3^k]; Array[A176763, 50, 0] (* _Paolo Xausa_, Apr 03 2024 *)
%o A176763 (Python)
%o A176763 def a(n):
%o A176763     k, strn = 0, str(n)
%o A176763     while strn not in str(3**k): k += 1
%o A176763     return 3**k
%o A176763 print([a(n) for n in range(33)]) # _Michael S. Branicky_, Apr 03 2024
%Y A176763 Cf. A000244, A030000, A030001, A063565, A018856.
%K A176763 base,easy,nonn
%O A176763 0,1
%A A176763 _Jonathan Vos Post_, Apr 25 2010
%E A176763 More terms from _Sean A. Irvine_ and _Jon E. Schoenfield_, May 05 2010
%E A176763 a(0) prepended by _Paolo Xausa_, Apr 03 2024