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A262205
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Primes that are the concatenation of n, prime(n) and n.
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2
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353, 7177, 9239, 113111, 5324153, 5726957, 5927759, 6934769, 8141981, 9750997, 101547101, 123677123, 131739131, 153883153, 1791063179, 1891129189, 2011229201, 2071279207, 2311453231, 2491579249, 2631669263, 2691723269, 2791801279
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OFFSET
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1,1
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LINKS
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EXAMPLE
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353 is a prime number that is concatenation of 3, prime(3) and 3.
7177 is a prime number that is concatenation of 7, prime(7) and 7.
9239 is a prime number that is concatenation of 9, prime(9) and 9.
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MATHEMATICA
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f[n_] := Block[{d = IntegerDigits@ n, p = IntegerDigits@ Prime@ n}, FromDigits@ Join[d, p, d]]; Select[f /@ Range@ 300, PrimeQ] (* Michael De Vlieger, Sep 15 2015 *)
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PROG
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(PARI) for(n=1, 1e3, if(isprime(k=eval(Str(n, prime(n), n))), print1(k", ")))
(Magma) [p: n in [1..400] | IsPrime(p) where p is Seqint(Intseq(n) cat Intseq(NthPrime(n)) cat Intseq(n))]; // Bruno Berselli, Sep 15 2015
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CROSSREFS
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KEYWORD
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nonn,easy,base
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AUTHOR
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STATUS
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approved
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