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A193459
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Total number of distinct divisors of all numbers that can be written by rearranging the digits of n in decimal representation.
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4
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1, 2, 2, 3, 2, 4, 2, 4, 3, 4, 2, 8, 3, 5, 6, 6, 3, 8, 5, 6, 8, 4, 7, 12, 8, 6, 13, 8, 7, 8, 3, 7, 4, 5, 5, 12, 3, 5, 6, 8, 5, 12, 5, 6, 11, 9, 5, 16, 6, 6, 6, 8, 5, 11, 4, 11, 8, 7, 5, 12, 6, 6, 12, 9, 11, 8, 7, 8, 14, 8, 3, 13, 3, 5, 8, 7, 4, 10, 3, 10, 8
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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1,2
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COMMENTS
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LINKS
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EXAMPLE
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a(20) = #{1,2,4,5,10,20} = 6;
a(21) = #{1,2,3,4,6,7,12,21} = 8;
a(22) = #{1,2,11,22} = 4;
a(23) = #{1,2,4,8,16,23,32} = 7;
a(24) = #{1,2,3,4,6,7,8,12,14,21,24,42} = 12;
a(25) = #{1,2,4,5,13,25,26,52} = 8;
a(26) = #{1,2,13,26,31,62} = 6;
a(27) = #{1,2,3,4,6,8,9,12,18,24,27,36,72} = 13;
a(28) = #{1,2,4,7,14,28,41,82} = 8;
a(29) = #{1,2,4,23,29,46,92} = 7.
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PROG
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(Haskell)
import Data.List (permutations, nub)
a193459 n =
length $ nub $ concatMap divisors $ map read $ permutations $ show n
where divisors n = filter ((== 0) . mod n) [1..n]
a193459_list = map a193459 [1..]
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CROSSREFS
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KEYWORD
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AUTHOR
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STATUS
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approved
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