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A091178
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Numbers k such that k-th prime is of the form 6*m+1.
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15
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4, 6, 8, 11, 12, 14, 18, 19, 21, 22, 25, 27, 29, 31, 34, 36, 37, 38, 42, 44, 46, 47, 48, 50, 53, 58, 59, 61, 63, 65, 67, 68, 70, 73, 74, 75, 78, 80, 82, 84, 85, 88, 90, 93, 95, 99, 100, 101, 105, 106, 110, 111, 112, 114, 115, 117, 121, 122, 125, 127, 129, 130
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OFFSET
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1,1
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COMMENTS
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Sequence A091177 (indices of primes of the form 3*k-1) is this sequence's complement in the positive integers without {2}. - M. F. Hasler, Sep 02 2016
The asymptotic density of this sequence is 1/2 (by Dirichlet's theorem). - Amiram Eldar, Feb 28 2021
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LINKS
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FORMULA
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MATHEMATICA
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Select[Range[200], IntegerQ[(Prime[#]-1)/6]&] (* Harvey P. Dale, Aug 25 2013 *)
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PROG
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(PARI) isok(n) = !((prime(n)-1) % 6); \\ Michel Marcus, Mar 04 2016
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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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