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A237890
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Primes p such that p^2 + 4 and p^2 + 10 are also primes.
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8
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3, 7, 13, 97, 487, 613, 743, 827, 883, 1117, 1987, 2477, 2887, 3863, 4483, 5153, 5557, 5683, 5923, 5953, 6287, 7643, 7937, 8093, 9323, 10343, 12377, 13033, 13063, 14087, 14767, 15373, 16937, 17713, 17987, 18257, 19013, 19333, 19753, 19853, 20287, 20873, 21673
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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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7 is prime and appears in the sequence because 7^2+4 = 53 and 7^2+10 = 59 are also primes.
97 is prime and appears in the sequence because 97^2+4 = 9413 and 97^2+10 = 9419 are also primes.
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MAPLE
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KD := proc() local a, b, d; a:=ithprime(n); b:=a^2+4; d:=a^2+10; if isprime (b) and isprime(d) then RETURN (a); fi; end: seq(KD(), n=1..5000);
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MATHEMATICA
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Select[Prime[Range[5000]], PrimeQ[#^2 + 4] && PrimeQ[#^2 + 10] &]
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PROG
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(PARI) s=[]; forprime(p=2, 25000, if(isprime(p^2+4) && isprime(p^2+10), s=concat(s, p))); s \\ Colin Barker, Feb 15 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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