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A038564
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Numbers whose list of divisors includes each digit 1-9 equally often.
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16
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54023, 54203, 55868, 500407, 556744, 769858, 1187666, 1566986, 1875098, 3545924, 5594156, 5733406, 5849014, 5908304, 6100594, 6712006, 7605544, 9106868, 9580654, 10909864, 23456789, 23458679, 23459687, 23465789, 23465987, 23469587, 23475869, 23478569, 23489657
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OFFSET
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1,1
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LINKS
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EXAMPLE
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55868 is a term because, among its divisors (which are 1, 2, 4, 13967, 27934, 55868), each digit from 1 through 9 occurs exactly twice.
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MATHEMATICA
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ld9Q[n_]:=Module[{d=DeleteCases[Sort[Flatten[IntegerDigits/@Divisors[ n]]], 0]}, Length[ Intersection[ d, Range[ 9]]] == 9&&Length[Union[ Length/@Split[ d]]]==1]; Select[ Range[ 235*10^5], ld9Q] (* Harvey P. Dale, Dec 20 2022 *)
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PROG
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(Python)
from sympy import divisors
from collections import Counter
def ok(n):
c = Counter()
for d in divisors(n, generator=True): c.update(str(d))
return len(set([c[i] for i in "123456789"])) == 1
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CROSSREFS
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KEYWORD
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nonn,base,easy
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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