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A165986
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Even semiprimes n such that the largest prime factor + 4 is prime.
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1
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6, 14, 26, 38, 74, 86, 134, 158, 194, 206, 218, 254, 326, 386, 446, 458, 554, 614, 626, 698, 758, 794, 878, 914, 926, 974, 998, 1226, 1286, 1346, 1478, 1514, 1538, 1646, 1706, 1718, 1754, 1766, 1814, 1874, 1934, 2018, 2174, 2186, 2426, 2558, 2594, 2606
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| Also numbers n of the form 2p such that p and p+4 are prime.
n is congruent to 2 modulo 3 for n > 6.
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FORMULA
| a(n) = 2*A023200(n). - R. J. Mathar, Jun 23 2011
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PROG
| (MAGMA) [ 2*p: p in PrimesUpTo(1500) | IsPrime(p+4) ]; // Klaus Brockhaus, Jun 26 2011
(PARI) forprime(p=2, 1e3, if(isprime(p+4), print1(p+p", "))) \\ Charles R Greathouse IV, Jun 26 2011
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CROSSREFS
| Sequence in context: A095794 A119867 A026055 * A131951 A168648 A093776
Adjacent sequences: A165983 A165984 A165985 * A165987 A165988 A165989
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KEYWORD
| nonn,easy
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AUTHOR
| Giovanni Teofilatto (g.teofilatto(AT)tiscalinet.it), Oct 03 2009, Jun 26 2011
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