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A193459 Total number of distinct divisors of all numbers that can be written by rearranging the digits of n in decimal representation. 4
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)
OFFSET
1,2
COMMENTS
a(n) >= A000005(n), a(A193460(n)) = A000005(A193460(n)).
LINKS
EXAMPLE
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.
PROG
(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..]
CROSSREFS
Cf. A047726.
Sequence in context: A066800 A368195 A218705 * A114102 A193513 A218704
KEYWORD
nonn,base,look
AUTHOR
Reinhard Zumkeller, Jul 26 2011
STATUS
approved

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Last modified June 16 15:45 EDT 2024. Contains 373432 sequences. (Running on oeis4.)