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A079703
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Numbers 4p where p is prime and 2p+1 and 4p+1 are composite.
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1
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68, 76, 124, 188, 236, 244, 284, 404, 412, 428, 436, 548, 596, 604, 628, 668, 724, 788, 844, 892, 908, 916, 964, 1028, 1052, 1076, 1084, 1132, 1244, 1252, 1268, 1324, 1348, 1388, 1396, 1412, 1468, 1516, 1532, 1556, 1588, 1604, 1684, 1756, 1796, 1828, 1844
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OFFSET
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0,1
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LINKS
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EXAMPLE
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2*17+1=35, 4*17+1=69, therefore 68 is in the sequence.
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MATHEMATICA
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Select[4*Prime[Range[90]], AllTrue[{#/2, #}+1, CompositeQ]&] (* Harvey P. Dale, Dec 28 2023 *)
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PROG
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(PARI) forprime (p=3, 200, if (!isprime(2*p+1) && !isprime(4*p+1), print1(4*p", ")))
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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