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Search: id:A113275
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| A113275 |
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Lesser of twin primes for which the gap before the following twin primes is a record. |
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3
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| 3, 5, 17, 41, 71, 311, 347, 659, 2381, 5879, 13397, 18539, 24419, 62297, 187907, 687521, 688451, 850349, 2868959, 4869911, 9923987, 14656517, 17382479, 30752231, 32822369, 96894041, 136283429, 234966929, 248641037, 255949949
(list; graph; listen)
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OFFSET
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1,1
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EXAMPLE
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The smallest twin prime pair is 3,5, then 5,7 so a(0)=3 and a(1)=5; the following pair is 11,13 so a(2)=5 because 11-5=6>5-3=2; the following pair is 17,19: since 17-11=6=11-5 nothing happens; the following pair is 29,31 so a(3)=17 because 29-17=12>11-5=6
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MATHEMATICA
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NextLowerTwinPrim[n_] := Block[{k = n + 2}, While[ !PrimeQ[k] || !PrimeQ[k + 2], k++ ]; k]; p = 3; r = 0; t = {3}; Do[q = NextLowerTwinPrim[p]; If[q > r + p, AppendTo[t, p]; r = q - p]; p = q, {n, 10^9}] (* Robert G. Wilson v *)
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CROSSREFS
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Record gaps are given in A113274. Cf. A002386.
Sequence in context: A148521 A148522 A141160 this_sequence A001572 A131342 A005142
Adjacent sequences: A113272 A113273 A113274 this_sequence A113276 A113277 A113278
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KEYWORD
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nonn
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AUTHOR
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Bernardo Boncompagni (redgolpe(AT)redgolpe.com), Oct 21 2005
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EXTENSIONS
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a(22)-a(30) from Robert G. Wilson v (rgwv(at)rgwv.com), Oct 22 2005
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