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Search: id:A141109
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| A141109 |
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Even numbers 2n such that for every prime p in [n,2n-2], 2n-p is also prime. |
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+0
2
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| 4, 6, 8, 10, 12, 14, 16, 18, 24, 30, 36, 42, 48, 60, 90, 210
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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The Deshouillers et al. paper proves that 210 is the last term. This sequence is the same as 2*A002271, but why?
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LINKS
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Jean-Marc Deshouillers, Andrew Granville, Wladyslaw Narkiewicz, and Carl Pomerance, An upper bound in Goldbach's problem, Math. Comp. 61 (1993), 209-213.
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EXAMPLE
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30 is in this sequence because the primes p between 15 and 28 are {17,19,23} and 30-p is {13,11,7}.
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MATHEMATICA
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t={}; Do[If[And@@PrimeQ[2n-Prime[Range[PrimePi[n-1]+1, PrimePi[2n-2]]]], AppendTo[t, 2n]], {n, 2, 105}]; t
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CROSSREFS
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Sequence in context: A093161 A111305 A134928 this_sequence A061344 A066664 A064938
Adjacent sequences: A141106 A141107 A141108 this_sequence A141110 A141111 A141112
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KEYWORD
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fini,full,nonn
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AUTHOR
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T. D. Noe (noe(AT)sspectra.com), Jun 03 2008
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