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Search: id:A164294
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| A164294 |
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Primes prime(k) such that all integers in [(prime(k-1)+1)/2,(prime(k)-1)/2] are composite, excluding those primes in A080359. |
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+0 13
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| 131, 151, 229, 233, 311, 571, 643, 727, 941, 1013, 1051, 1153, 1373, 1531, 1667, 1669, 1723, 1783, 1787, 1831, 1951, 1979, 2029, 2131, 2213, 2239, 2311, 2441, 2593, 2621, 2633, 2659, 2663, 2887, 3001, 3011, 3019, 3121, 3169, 3209, 3253, 3347, 3413, 3457
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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The primes of A080359 larger than 3 all have the property that the integers in the
interval selected by halving the value of the preceding prime and halving their own
value are all composite. This sequence here collects the primes that are not in A080359
but still share this property of the prime-free sub-interval.
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LINKS
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V. Shevelev, On critical small intervals containing primes, arXiv:0908.2319 [From Vladimir Shevelev (shevelev(AT)bgu.ac.il), Aug 20 2009]
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FORMULA
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A164333 \ A080359.
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EXAMPLE
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For the prime 1531=A000040(242), the preceding prime is A000040(241)=1523, and
the integers from (1523+1)/2 = 762 up to (1531-1)/2 = 765 are all composite, as
they fall in the gap between A000040(135) and A000040(136). In addition, 1531 is not in
A080359, which adds 1531 to this sequence here.
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CROSSREFS
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Cf. A080359, A104272, A164288, A001262, A001567, A062568, A141232
Sequence in context: A039558 A045164 A134951 this_sequence A155924 A090264 A132254
Adjacent sequences: A164291 A164292 A164293 this_sequence A164295 A164296 A164297
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KEYWORD
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nonn
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AUTHOR
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Vladimir Shevelev (shevelev(AT)bgu.ac.il), Aug 12 2009
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EXTENSIONS
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Extended beyond 571 by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Oct 02 2009
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