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Search: id:A087941
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| A087941 |
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a(n) = the number of consecutive primes x-2,x+2 such that x=j*(p(n)#/2)/p(k), where 1<=j<p(n+1) and 2<=k<=n and p(k) doesn't divide j. |
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+0
3
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| 0, 0, 1, 3, 7, 4, 4, 6, 7, 9, 7, 8, 8, 6, 9, 9, 7, 7, 6, 10, 9, 10, 5, 9, 10, 5, 8, 10, 13, 8, 15, 7, 6, 13, 8, 7, 8, 14, 13, 13, 11, 11, 7, 11, 10, 8, 11
(list; graph; listen)
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OFFSET
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1,4
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COMMENT
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p(n) is the n-th prime; # denotes primorial (A002110).
a(n) seems to grow like 2 log p(n).
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EXAMPLE
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a(4)=3 because for j,k=(1,3),(1,4),(3,4), j*(7#/2)/p(k)+-2 are consecutive primes.
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CROSSREFS
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Cf. A002110, A087859, A088968.
Sequence in context: A010471 A077226 A163335 this_sequence A021271 A094689 A019831
Adjacent sequences: A087938 A087939 A087940 this_sequence A087942 A087943 A087944
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KEYWORD
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nonn
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AUTHOR
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Pierre CAMI (colettecami(AT)aol.com), Oct 27 2003
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EXTENSIONS
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Edited by Don Reble (djr(AT)nk.ca), Nov 16 2005
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