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Search: id:A161403
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| A161403 |
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Numbers n such that the count of primes among the permutations of the digits of n is greater than 3. |
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+0
1
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| 107, 149, 170, 179, 194, 197, 379, 397, 419, 491, 701, 709, 710, 719, 739, 790, 791, 793, 907, 914, 917, 937, 941, 970, 971, 973, 1003, 1007, 1009, 1012, 1013, 1015, 1016, 1018, 1019, 1021, 1024, 1028, 1030, 1031, 1033, 1036, 1037, 1039, 1042, 1049, 1051
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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Leading zeros in the permutations are ignored.
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LINKS
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C. Hilliard, Comments and PARI program.
Wikipedia, Permutation
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EXAMPLE
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107 has four permutations of its digits 1, 0, 7 that form a prime, namely 107, 017, 071, 701. So the count of primes for 107 is greater than 3 and 107 is in the sequence.
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PROGRAM
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(PARI) Cf. C. Hilliard link.
(MAGMA) [ n: n in [1..1060] | #[ s: s in Seqset([ Seqint([m(p[i]):i in [1..#x] ], 10): p in Permutations(Seqset(x)) ]) | IsPrime(s) ] gt 3 where m is map< x->y | [<x[i], y[i]>:i in [1..#x] ] > where x is [1..#y] where y is Intseq(n, 10) ]; [From Klaus Brockhaus, Jun 14 2009]
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CROSSREFS
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Sequence in context: A033258 A095647 A039555 this_sequence A142662 A107215 A142142
Adjacent sequences: A161400 A161401 A161402 this_sequence A161404 A161405 A161406
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KEYWORD
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base,nonn
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AUTHOR
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Cino Hilliard (hillcino368(AT)hotmail.com), Jun 09 2009
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EXTENSIONS
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Edited by Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Jun 14 2009
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