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A173145
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Numbers n such that neither prime(n-1) nor prime(n+1) is of form 6k-1.
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1
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3, 5, 7, 13, 20, 26, 28, 30, 35, 37, 43, 45, 47, 49, 60, 62, 64, 66, 69, 74, 79, 81, 83, 89, 94, 100, 111, 113, 116, 126, 128, 130, 132, 135, 137, 142, 144, 146, 148, 150, 152, 154, 156, 158, 168, 173, 176, 178, 180, 182, 188, 190, 192, 203, 212, 223, 225, 230, 232
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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1,1
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LINKS
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Harvey P. Dale, Table of n, a(n) for n = 1..1000
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EXAMPLE
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a(1)=3 because prime(3-1)=3 and prime(3+1)=7 are not of the form 6k-1.
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MATHEMATICA
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pnQ[n_]:=NoneTrue[{Prime[n-1], Prime[n+1]}, IntegerQ[(#+1)/6]&]; Select[ Range[ 2, 300], pnQ] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Dec 04 2019 *)
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CROSSREFS
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Cf. A007528.
Sequence in context: A187872 A180450 A051507 * A060274 A005235 A107664
Adjacent sequences: A173142 A173143 A173144 * A173146 A173147 A173148
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KEYWORD
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nonn,easy,less
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AUTHOR
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Juri-Stepan Gerasimov, Feb 11 2010
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EXTENSIONS
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1 removed, 113 inserted - R. J. Mathar, Mar 09 2010
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STATUS
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approved
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