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A078241
Smallest multiple of n using only digits 0 and 2.
21
2, 2, 222, 20, 20, 222, 2002, 200, 222222222, 20, 22, 2220, 2002, 2002, 2220, 2000, 22202, 222222222, 22002, 20, 20202, 22, 220202, 22200, 200, 2002, 2202222222, 20020, 2202202, 2220, 222022, 20000, 222222, 22202, 20020, 2222222220, 222
OFFSET
1,1
COMMENTS
a(n) = min{A169965(k): k > 1 and A169965(k) mod n = 0}. - Reinhard Zumkeller, Jan 10 2012
LINKS
Reinhard Zumkeller and Chai Wah Wu, Table of n, a(n) for n = 1..9998 First 998 terms from Reinhard Zumkeller.
FORMULA
a(n) < 10^n / (0.45 n). - Charles R Greathouse IV, Jan 09 2012
a(n) <= A216812(n) <= 2(10^n - 1)/9. - N. J. A. Sloane, Sep 18 2012
MATHEMATICA
Module[{m=Rest[FromDigits/@Tuples[{0, 2}, 12]]}, Table[Select[m, Divisible[ #, n]&, 1], {n, 40}]]//Flatten (* Harvey P. Dale, Jul 31 2017 *)
PROG
(Haskell)
a078241 n = head [x | x <- tail a169965_list, mod x n == 0]
-- Reinhard Zumkeller, Jan 10 2012
(Python)
def A078241(n):
if n > 0:
for i in range(1, 2**n):
x = 2*int(bin(i)[2:])
if not x % n:
return x
return 0 # Chai Wah Wu, Dec 30 2014
KEYWORD
base,nonn
AUTHOR
Amarnath Murthy, Nov 23 2002
EXTENSIONS
More terms from Ray Chandler, Jul 12 2004
STATUS
approved