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Search: id:A096840
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| A096840 |
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a[n]=x is the least number so that around x^2 (the center) the number of primes is equal to n. The radius of neighborhood is Ceiling[Log[x^2]. |
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+0
9
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| 1, 6, 3, 2, 14, 36, 117, 1652, 9582, 41361, 908637
(list; graph; listen)
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OFFSET
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1,2
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EXAMPLE
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n=9: a[9]=41361, center=1710732321, radius=22, the nine primes in the zone are {1710732299, 1710732307, 1710732311, 1710732313, 1710732319, 1710732323, 1710732329, 1710732337, 1710732343}
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MATHEMATICA
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f[n_] := (PrimePi[n^2 + Ceiling[ Log[n^2]]] - PrimePi[n^2 - Ceiling[ Log[n^2]] - 1]); t = Table[0, {15}]; Do[a = f[n]; If[a < 15 && t[[a + 1]] == 0, t[[a + 1]] = n], {n, 10^5}] (from Robert G. Wilson v Jul 14 2004)
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CROSSREFS
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Cf. A096509-A096523, A096830-A096839.
Sequence in context: A076214 A011488 A021162 this_sequence A096685 A085670 A011410
Adjacent sequences: A096837 A096838 A096839 this_sequence A096841 A096842 A096843
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KEYWORD
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more,nonn
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AUTHOR
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Labos E. (labos(AT)ana.sote.hu), Jul 14 2004
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