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A063643
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Primes with 2 representations: p*q - 2 = u*v + 2 where p, q, u and v are primes.
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14
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23, 37, 53, 67, 89, 113, 131, 157, 211, 251, 293, 307, 337, 379, 409, 449, 487, 491, 499, 503, 631, 683, 701, 719, 751, 769, 787, 919, 941, 953, 991, 1009, 1039, 1117, 1193, 1201, 1259, 1381, 1399, 1439, 1459, 1471, 1499, 1511, 1567, 1709, 1733, 1759, 1801
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OFFSET
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1,1
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COMMENTS
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Or, primes p such that p+/-2 are semiprimes. - Zak Seidov, Mar 08 2006
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LINKS
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FORMULA
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EXAMPLE
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MAPLE
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q:= p-> isprime(p) and map(numtheory[bigomega], {p-2, p+2})={2}:
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MATHEMATICA
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Select[Prime[Range[300]], PrimeOmega[#+2] == PrimeOmega[#-2] == 2&] (* Jean-François Alcover, Mar 02 2019 *)
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PROG
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(PARI) { n=0; for (m=2, 10^9, p=prime(m); if (bigomega(p + 2) == 2 && bigomega(p - 2) == 2, write("b063643.txt", n++, " ", p); if (n==1000, break)) ) } \\ Harry J. Smith, Aug 26 2009
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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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