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A237713 Composite numbers n such that the distinct digits in n and the distinct digits in the proper divisors of n are the same. 2
125, 1255, 2510, 11009, 11099, 11255, 11379, 12326, 12955, 14379, 14397, 15033, 15303, 16325, 17482, 21109, 25105, 31007, 31503, 33011, 35213, 37127, 37921, 41303, 44011, 49319, 51367, 53491, 63013, 69413, 70319, 71057, 72013, 72517, 74341, 77011, 81767 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Since 1 is always a divisor of n, this is a subsequence of A011531. - Michel Marcus, Feb 12 2014

LINKS

Giovanni Resta, Table of n, a(n) for n = 1..10000

EXAMPLE

125 is in the sequence because the proper divisors of 125 are {1, 5, 25} with the same digits as 125.

MATHEMATICA

Pn[n_]:=Sort[DeleteDuplicates[Flatten[IntegerDigits[Take[Divisors[n], DivisorSigma[0, n]-1]]]]]; Fn[n_]:=Sort[DeleteDuplicates[IntegerDigits[n]]]; lst={}; Do[If[!PrimeQ[n]&&Pn[n]===Fn[n], AppendTo[lst, n]], {n, 2, 10^5}]; lst

Select[Range[10^5], ! PrimeQ@# && Union@ IntegerDigits@ # == Union @@ IntegerDigits /@ Most@ Divisors@ # &] (* Giovanni Resta, Feb 12 2014 *)

PROG

(PARI) isok(n) = { my(digs = []); fordiv(n, d, if (d != n, digs = concat(digs, digits(d)))); (n != 1) && !isprime(n) && vecsort(digs, , 8) == vecsort(digits(n), , 8); } \\ Michel Marcus, Feb 12 2014

CROSSREFS

Cf. A032741, A035141.

See A282755 for a variant.

Sequence in context: A016851 A204795 A243240 * A000526 A016971 A030082

Adjacent sequences:  A237710 A237711 A237712 * A237714 A237715 A237716

KEYWORD

nonn,base

AUTHOR

Michel Lagneau, Feb 12 2014

STATUS

approved

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Last modified October 17 18:51 EDT 2019. Contains 328127 sequences. (Running on oeis4.)