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A271211
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Composite integers sandwiched between primes p, q with q-p = 4.
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3
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8, 9, 10, 14, 15, 16, 20, 21, 22, 38, 39, 40, 44, 45, 46, 68, 69, 70, 80, 81, 82, 98, 99, 100, 104, 105, 106, 110, 111, 112, 128, 129, 130, 164, 165, 166, 194, 195, 196, 224, 225, 226, 230, 231, 232, 278, 279, 280, 308, 309, 310, 314, 315, 316, 350, 351, 352, 380
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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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The composite number 8 is sandwiched between primes 7 and 11, and 11-7=4, so 8 is a member of the sequence.
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MATHEMATICA
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Range[#[[1]]+1, #[[2]]-1]&/@Select[Partition[Prime[Range[100]], 2, 1], #[[2]]- #[[1]] == 4&]//Flatten (* Harvey P. Dale, Oct 12 2019 *)
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PROG
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(PARI) lista(nn) = {forcomposite(c=4, nn, if ((p=precprime(c)) && ((nextprime(c)-p)==4), print1(c, ", ")); ); }
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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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