cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A095050 Numbers such that all ten digits are needed to write all positive divisors in decimal representation.

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%I A095050 #31 Nov 16 2022 13:53:11
%S A095050 108,216,270,304,306,312,324,360,380,406,432,450,504,540,570,608,612,
%T A095050 624,630,648,654,702,708,714,720,728,756,760,780,810,812,864,870,900,
%U A095050 910,912,918,924,936,945,954,972,980,1008,1014,1026,1032,1036,1038
%N A095050 Numbers such that all ten digits are needed to write all positive divisors in decimal representation.
%C A095050 A095048(a(n)) = 10.
%C A095050 Numbers n such that A037278(n), A176558(n) and A243360(n) contain 10 distinct digits. - _Jaroslav Krizek_, Jun 19 2014
%C A095050 Once a number is in the sequence, then all its multiples will be there too. The list of primitive terms begin: 108, 270, 304, 306, 312, 360, 380, ... - _Michel Marcus_, Jun 20 2014
%C A095050 Pandigital numbers A050278 and A171102 are subsequences. - _Michel Marcus_, May 01 2020
%H A095050 Reinhard Zumkeller, <a href="/A095050/b095050.txt">Table of n, a(n) for n = 1..10000</a>
%F A095050 a(n) ~ n. - _Charles R Greathouse IV_, Nov 16 2022
%e A095050 Divisors of 108 are: [1, 2, 3, 4, 6, 9, 12, 18, 27, 36, 54, 108] where all digits can be found.
%p A095050 q:= n-> is({$0..9}=map(x-> convert(x, base, 10)[], numtheory[divisors](n))):
%p A095050 select(q, [$1..2000])[];  # _Alois P. Heinz_, Oct 28 2021
%t A095050 Select[Range@2000, 1+Union@@IntegerDigits@Divisors@# == Range@10 &] (* _Hans Rudolf Widmer_, Oct 28 2021 *)
%o A095050 (Haskell)
%o A095050 import Data.List (elemIndices)
%o A095050 a095050 n = a095050_list !! (n-1)
%o A095050 a095050_list = map (+ 1) $ elemIndices 10 $ map a095048 [1..]
%o A095050 -- _Reinhard Zumkeller_, Feb 05 2012
%o A095050 (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
%o A095050 (Python)
%o A095050 from sympy import divisors
%o A095050 def ok(n):
%o A095050     digits_used = set()
%o A095050     for d in divisors(n):
%o A095050         digits_used |= set(str(d))
%o A095050     return len(digits_used) == 10
%o A095050 print([k for k in range(1040) if ok(k)]) # _Michael S. Branicky_, Oct 28 2021
%Y A095050 Cf. A095048, A059436 (subsequence), A206159.
%Y A095050 Cf. A243543 (the smallest number m whose list of divisors contains n distinct digits).
%Y A095050 Sequences of numbers n such that the list of divisors of n contains k distinct digits for 1 <= k <= 10: k = 1: A243534; k = 2: A243535; k = 3: A243536; k = 4: A243537; k = 5: A243538; k = 6: A243539; k = 7: A243540; k = 8: A243541; k = 9: A243542; k = 10: A095050. - _Jaroslav Krizek_, Jun 19 2014
%Y A095050 Cf. A050278, A171102.
%K A095050 nonn,base
%O A095050 1,1
%A A095050 _Reinhard Zumkeller_, May 28 2004