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A253245
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Primes that are the concatenation of prime(n) and prime(n+2).
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1
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37, 1117, 1319, 1723, 4759, 89101, 97103, 101107, 113131, 151163, 181193, 223229, 227233, 239251, 251263, 293311, 313331, 337349, 389401, 421433, 461467, 491503, 587599, 631643, 647659, 683701, 691709, 701719, 739751, 761773, 809821
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OFFSET
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1,1
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LINKS
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Harvey P. Dale, Table of n, a(n) for n = 1..1000
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MATHEMATICA
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Module[{nn=300, pr}, pr={#[[1]], #[[3]]}&/@Partition[Prime[Range[nn]], 3, 1]; Select[Table[FromDigits[Flatten[IntegerDigits/@pr[[n]]]], {n, Length[ pr]}], PrimeQ]] (* Harvey P. Dale, Nov 29 2015 *)
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PROG
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(PARI) for(n=1, 1e3, if(isprime(k=eval(Str(prime(n), prime(n+2)))), print1(k", ")))
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CROSSREFS
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Cf. A000040, A030461.
Sequence in context: A217454 A101631 A005390 * A168166 A168165 A340539
Adjacent sequences: A253242 A253243 A253244 * A253246 A253247 A253248
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KEYWORD
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nonn,easy,base
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AUTHOR
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Altug Alkan, Aug 22 2015
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STATUS
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approved
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