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A107073
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Numbers n such that the string 35n is prime.
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0
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3, 9, 11, 17, 27, 29, 33, 39, 41, 47, 57, 59, 71, 81, 83, 93, 107, 111, 117, 129, 141, 149, 153, 159, 171, 201, 221, 227, 251, 257, 267, 279, 281, 291, 311, 317, 323, 327, 339, 353, 363, 381, 393, 401, 407, 419, 423, 437, 447, 449, 461, 491, 507, 509, 521, 527
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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EXAMPLE
| If n=47 then 3547 is prime.
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MAPLE
| A055642 := proc(n) max(1, ilog10(n)+1) ; end: cat2 := proc(a, b) a*10^A055642(b)+b ; end: for n from 1 to 1000 do if isprime( cat2(35, n) ) then printf("%d, ", n) ; fi; od: [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jan 16 2009]
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PROG
| (MAGMA) [ n: n in [1..900] | IsPrime(Seqint(Intseq(n) cat [5, 3])) ]; [From Vincenzo Librandi, Feb 03 2011]
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CROSSREFS
| Cf. A032666. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jan 16 2009]
Sequence in context: A050538 A062227 A111324 * A173394 A111211 A144181
Adjacent sequences: A107070 A107071 A107072 * A107074 A107075 A107076
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KEYWORD
| nonn,base
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AUTHOR
| Parthasarathy Nambi (PachaNambi(AT)yahoo.com), Jun 07 2005
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