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A084294
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Number of primes in [p(n),n+p(n)] closed interval, where p(n) is the n-th prime.
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1
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2, 2, 2, 2, 2, 3, 3, 2, 3, 3, 3, 4, 4, 3, 4, 4, 5, 5, 5, 5, 4, 5, 5, 7, 6, 6, 5, 5, 5, 5, 7, 7, 7, 7, 8, 7, 8, 9, 8, 8, 7, 7, 9, 8, 9, 8, 9, 11, 10, 10, 11, 10, 10, 9, 10, 11, 10, 9, 9, 9, 8, 10, 11, 11, 10, 11, 12, 12, 12, 12, 12, 12, 13, 13, 13, 13, 14, 14, 14, 14, 15, 15, 15, 14, 15, 14, 13
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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FORMULA
| a(n)=Pi[n+p(n)]=A000720(n+A000040(n))
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MATHEMATICA
| t[x_] := Table[w, {w, Prime[x], x+Prime[x]}] Table[Count[PrimeQ[t[n]], True], {n, 1, 128}] or Table[PrimePi[n+Prime[n]]-n+1, {n, 1, 25}];
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CROSSREFS
| Cf. A000040, A000720, A061067, A061068, A084295.
Sequence in context: A067743 A029230 A196067 * A067752 A025422 A078640
Adjacent sequences: A084291 A084292 A084293 * A084295 A084296 A084297
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KEYWORD
| nonn
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AUTHOR
| Labos E. (labos(AT)ana.sote.hu), May 27 2003
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