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A238242
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Primes p such that p^2+p+41 is also prime.
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4
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2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 97, 101, 103, 107, 113, 131, 137, 139, 149, 151, 157, 167, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 241, 257, 263, 269, 277, 281, 293, 307, 311, 313, 317, 337, 353
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OFFSET
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1,1
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COMMENTS
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n^2 + n + 41 is Euler’s prime generating polynomial.
The first 12 terms in the sequence are the first 12 consecutive primes.
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LINKS
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EXAMPLE
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13 is in the sequence because 13 is prime and 13^2+13+41 = 223 is also prime.
113 is in the sequence because 113 is prime and 113^2+113+41 = 12923 is also prime.
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MAPLE
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with(numtheory):KD := proc() local a, b; a:=ithprime(n); b:=a^2+a+41; if isprime(b) then RETURN (a); fi; end: seq(KD(), n=1..500);
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MATHEMATICA
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Select[Prime[Range[200]], PrimeQ[#^2+#+41]&]
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PROG
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(PARI) s=[]; forprime(p=2, 1000, if(isprime(p^2+p+41), s=concat(s, p))); s \\ Colin Barker, Feb 20 2014
(Magma) [p: p in PrimesUpTo(400)| IsPrime(p^2+p+41)]; // Vincenzo Librandi, Feb 22 2014
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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