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 A059436 Smallest number whose set of divisors contains each digit 0-9 at least n times. 4
 108, 540, 1140, 1890, 3420, 5460, 7980, 11760, 16380, 29700, 23520, 23760, 44460, 38220, 51480, 47880, 41580, 97020, 87780, 71820, 98280, 103740, 83160, 154440, 124740, 143640, 207480, 166320, 278460, 382200, 263340, 249480, 311220, 335160 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Robert G. Wilson v, Table of n, a(n) for n = 1..402 . Erich Friedman, What's Special About This Number? (See entry 7980.) EXAMPLE The divisors of 540 are 1, 2, 3, 4, 5, 6, 9, 10, 12, 15, 18, 20, 27, 30, 36, 45, 54, 60, 90, 108, 135, 180, 270, 540 and every digit appears at least twice in this list. MATHEMATICA f[n_] := Block[{s = Transpose@ Tally[ Sort[ Flatten[ IntegerDigits@# & /@ Divisors@ n]]]}, If[First@s == {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}, Min@ Last@s, 0]]; t = Table[0, {50}]; k = 6; While[k < 400000, a = f@k; If[ t[[a]] == 0, t[[a]] = k; Print[{a, k}]]; k += 6]; t [From Robert G. Wilson v, Jul 31 2010] PROG (Haskell) import Data.List (group, sort) a059436 n = head [x | x <- [1..],    let dds = map length \$ group \$ sort \$ concatMap show \$ a027750_row x,    minimum dds == n, length dds == 10] -- Reinhard Zumkeller, Feb 04 2012 CROSSREFS Cf. A027750; subsequence of A095050, A095048. Sequence in context: A224526 A251270 A063880 * A233685 A160919 A129027 Adjacent sequences:  A059433 A059434 A059435 * A059437 A059438 A059439 KEYWORD base,nonn,nice AUTHOR Erich Friedman, Feb 01 2001 EXTENSIONS More terms from David W. Wilson, Aug 31 2001 Offset corrected by R. J. Mathar, Jun 02 2010 STATUS approved

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Last modified December 21 20:27 EST 2014. Contains 252326 sequences.