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Search: id:A136721
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| A136721 |
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Prime quadruples: 3rd term. |
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+0
2
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| 11, 17, 107, 197, 827, 1487, 1877, 2087, 3257, 3467, 5657, 9437, 13007, 15647, 15737, 16067, 18047, 18917, 19427, 21017, 22277, 25307, 31727, 34847, 43787, 51347, 55337, 62987, 67217, 69497, 72227, 77267, 79697, 81047, 82727, 88817, 97847
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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Primes p such that p-6, p-4, and p+2 are prime. Apart from the first term, a(n) = 17 (mod 30).
The members of each quadruple are twin primes when they are 1st and 2nd terms and when 3rd and 4th terms. When they are 2nd and 3rd terms they differ by 4.
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EXAMPLE
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The four terms in the first quadruple are 5,7,11,13 and in the 2nd 11,13,17,19. The four terms or members of each set must be simultaneously prime.
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MATHEMATICA
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lst={}; Do[p0=Prime[n]; If[PrimeQ[p2=p0+2], If[PrimeQ[p6=p0+6], If[PrimeQ[p8=p0+8], AppendTo[lst, p6]]]], {n, 12^4}]; lst [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Aug 22 2008]
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CROSSREFS
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Cf. A007530 A090258 A136720.
Sequence in context: A146036 A046122 A102870 this_sequence A107172 A090286 A056577
Adjacent sequences: A136718 A136719 A136720 this_sequence A136722 A136723 A136724
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KEYWORD
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easy,nonn
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AUTHOR
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Enoch Haga (Enokh(AT)comcast.net), Jan 18 2008
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EXTENSIONS
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Edited by Charles R Greathouse IV (charles.greathouse(AT)case.edu), Oct 11 2009
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