A095050 Numbers such that all ten digits are needed to write all positive divisors in decimal representation.
108, 216, 270, 304, 306, 312, 324, 360, 380, 406, 432, 450, 504, 540, 570, 608, 612, 624, 630, 648, 654, 702, 708, 714, 720, 728, 756, 760, 780, 810, 812, 864, 870, 900, 910, 912, 918, 924, 936, 945, 954, 972, 980, 1008, 1014, 1026, 1032, 1036, 1038
Offset: 1
Examples
Divisors of 108 are: [1, 2, 3, 4, 6, 9, 12, 18, 27, 36, 54, 108] where all digits can be found.
Links
- Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
Crossrefs
Cf. A243543 (the smallest number m whose list of divisors contains n distinct digits).
Programs
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Haskell
import Data.List (elemIndices) a095050 n = a095050_list !! (n-1) a095050_list = map (+ 1) $ elemIndices 10 $ map a095048 [1..] -- Reinhard Zumkeller, Feb 05 2012
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Maple
q:= n-> is({$0..9}=map(x-> convert(x, base, 10)[], numtheory[divisors](n))): select(q, [$1..2000])[]; # Alois P. Heinz, Oct 28 2021
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Mathematica
Select[Range@2000, 1+Union@@IntegerDigits@Divisors@# == Range@10 &] (* Hans Rudolf Widmer, Oct 28 2021 *)
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PARI
isok(m)=my(d=divisors(m), v=[1]); for (k=2, #d, v = Set(concat(v, digits(d[k]))); if (#v == 10, return (1));); #v == 10; \\ Michel Marcus, May 01 2020
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Python
from sympy import divisors def ok(n): digits_used = set() for d in divisors(n): digits_used |= set(str(d)) return len(digits_used) == 10 print([k for k in range(1040) if ok(k)]) # Michael S. Branicky, Oct 28 2021
Formula
a(n) ~ n. - Charles R Greathouse IV, Nov 16 2022
Comments