cp's OEIS Frontend

A078242 Smallest multiple of n using only digits 0 and 3.

%I A078242 #24 May 31 2025 16:44:33
%S A078242 3,30,3,300,30,30,3003,3000,333,30,33,300,3003,30030,30,30000,33303,
%T A078242 3330,33003,300,3003,330,330303,3000,300,30030,333333333,300300,
%U A078242 3303303,30,333033,300000,33,333030,30030,33300,333,330030,3003,3000,33333
%N A078242 Smallest multiple of n using only digits 0 and 3.
%C A078242 a(n) = min{A169966(k): k > 1 and A169966(k) mod n = 0}. - _Reinhard Zumkeller_, Jan 10 2012
%H A078242 Reinhard Zumkeller and Chai Wah Wu, <a href="/A078242/b078242.txt">Table of n, a(n) for n = 1..10000</a> First 1000 terms from Reinhard Zumkeller
%t A078242 With[{lst=Rest[FromDigits/@Tuples[{0,3},10]]},Table[SelectFirst[lst,Mod[#,n]==0&],{n,50}]] (* _Harvey P. Dale_, May 31 2025 *)
%o A078242 (Haskell)
%o A078242 a078242 n = head [x | x <- tail a169966_list, mod x n == 0]
%o A078242 -- _Reinhard Zumkeller_, Jan 10 2012
%o A078242 (Python)
%o A078242 def A078242(n):
%o A078242     if n > 0:
%o A078242         for i in range(1,2**n):
%o A078242             x = 3*int(bin(i)[2:])
%o A078242             if not x % n:
%o A078242                 return x
%o A078242     return 0 # _Chai Wah Wu_, Dec 31 2014
%Y A078242 Cf. A004290, A078241-A078248, A079339, A096681-A096688.
%K A078242 base,nonn
%O A078242 1,1
%A A078242 _Amarnath Murthy_, Nov 23 2002
%E A078242 More terms from _Ray Chandler_, Jul 12 2004