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A256824
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Reverse concatenation of distinct digits of all divisors of n in base 10.
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11
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1, 21, 31, 421, 51, 6321, 71, 8421, 931, 5210, 1, 64321, 31, 7421, 531, 86421, 71, 986321, 91, 54210, 7321, 21, 321, 864321, 521, 6321, 97321, 87421, 921, 653210, 31, 864321, 31, 74321, 7531, 9864321, 731, 98321, 931, 854210, 41, 764321, 431, 421, 95431, 64321
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OFFSET
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1,2
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COMMENTS
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Concatenation of elements of set of all digits of all divisors of n in decreasing order in base 10.
There are precisely 512 distinct terms of this sequence - see A256825 (possible values of a(n) in increasing order).
Minimal term is 1, maximal term is 9876543210.
Numbers n such that a(n) = 1 are in A243534, numbers n such that a(n) = 9876543210 are in A095050.
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LINKS
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EXAMPLE
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For n = 12; list of divisors of 12 in base 10: 1, 2, 3, 4, 6, 12 contains five distinct digits (1, 2, 3, 4, 6) whose reverse concatenation is 64321.
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MATHEMATICA
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Table[FromDigits[Reverse[Union[Flatten[IntegerDigits[Divisors[n]]]]]], {n, 100}] (* Ivan N. Ianakiev, Apr 14 2015 *)
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PROG
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(Magma) [Seqint(Setseq(Set(Sort(&cat[Intseq(d): d in Divisors(n)])))): n in [1..100]]
(PARI) a(n) = {my(v = []); fordiv(n, d, v = vecsort(concat(v, digits(d)), , 8)); subst(Polrev(v), x, 10); } \\ Michel Marcus, Apr 11 2015
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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STATUS
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approved
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