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A078241 Smallest multiple of n using only digits 0 and 2.

%I A078241 #35 Apr 09 2020 10:29:41
%S A078241 2,2,222,20,20,222,2002,200,222222222,20,22,2220,2002,2002,2220,2000,
%T A078241 22202,222222222,22002,20,20202,22,220202,22200,200,2002,2202222222,
%U A078241 20020,2202202,2220,222022,20000,222222,22202,20020,2222222220,222
%N A078241 Smallest multiple of n using only digits 0 and 2.
%C A078241 a(n) = min{A169965(k): k > 1 and A169965(k) mod n = 0}. - _Reinhard Zumkeller_, Jan 10 2012
%H A078241 Reinhard Zumkeller and Chai Wah Wu, <a href="/A078241/b078241.txt">Table of n, a(n) for n = 1..9998</a> First 998 terms from Reinhard Zumkeller.
%F A078241 a(n) < 10^n / (0.45 n). - _Charles R Greathouse IV_, Jan 09 2012
%F A078241 a(n) <= A216812(n) <= 2(10^n - 1)/9. - _N. J. A. Sloane_, Sep 18 2012
%t A078241 Module[{m=Rest[FromDigits/@Tuples[{0,2},12]]},Table[Select[m,Divisible[ #,n]&,1],{n,40}]]//Flatten (* _Harvey P. Dale_, Jul 31 2017 *)
%o A078241 (Haskell)
%o A078241 a078241 n = head [x | x <- tail a169965_list, mod x n == 0]
%o A078241 -- _Reinhard Zumkeller_, Jan 10 2012
%o A078241 (Python)
%o A078241 def A078241(n):
%o A078241     if n > 0:
%o A078241         for i in range(1,2**n):
%o A078241             x = 2*int(bin(i)[2:])
%o A078241             if not x % n:
%o A078241                 return x
%o A078241     return 0 # _Chai Wah Wu_, Dec 30 2014
%Y A078241 Cf. A004290, A078242-A078248, A079339, A096681-A096688, A181060, A181061, A216481, A216812.
%K A078241 base,nonn
%O A078241 1,1
%A A078241 _Amarnath Murthy_, Nov 23 2002
%E A078241 More terms from _Ray Chandler_, Jul 12 2004