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 A236673 #23 May 22 2025 10:21:36 %S A236673 39,45,47,48,53,57,60,61,62,63,64,65,67,69,70,71,72,73,74,76,77,78,79, %T A236673 80,82,83,85,86,87,88,89,90,92,93,94,95,96,97,98,99,102,103,105,107, %U A236673 108,109,110,111,112,113,114,115,116,117,118,119,120,121,122,123 %N A236673 Exponents of powers of 3 that contain all ten decimal digits. %C A236673 It is conjectured that after a(43), a(n) = n + 63 (i.e., natural numbers beginning with 107). %C A236673 Complement of A236674. %H A236673 Seiichi Manyama, <a href="/A236673/b236673.txt">Table of n, a(n) for n = 1..10000</a> %e A236673 3^53 = 19383245667680019896796723, which contains two 1's, two 2's, three 3's, one 4, one 5, five 6's, three 7's, three 8's, four 9's and two 0's, so 53 is in the sequence. %e A236673 3^57 = 1570042899082081611640534563, which contains four 1's, two 2's, two 3's, three 4's, three 5's, three 6's, one 7, three 8's, two 9's and five 0's. %e A236673 58 is not in the sequence because there are no 5's in 3^58 = 4710128697246244834921603689. %t A236673 Select[Range[0, 200], Union[IntegerDigits[3^#]] == Range[0, 9] &] (* _T. D. Noe_, Jan 29 2014 *) %o A236673 (Python) %o A236673 def PanDig(x): %o A236673 a = '1234567890' %o A236673 for n in range(10**3): %o A236673 count = 0 %o A236673 for i in a: %o A236673 if str(x**n).count(i) > 0: %o A236673 count += 1 %o A236673 else: %o A236673 break %o A236673 if count == len(a): %o A236673 print(n) %Y A236673 Cf. A130694, A236674. %K A236673 nonn,base %O A236673 1,1 %A A236673 _Derek Orr_, Jan 29 2014