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A051697
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Closest prime to n (break ties by taking the smaller prime).
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22
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2, 2, 2, 3, 3, 5, 5, 7, 7, 7, 11, 11, 11, 13, 13, 13, 17, 17, 17, 19, 19, 19, 23, 23, 23, 23, 23, 29, 29, 29, 29, 31, 31, 31, 31, 37, 37, 37, 37, 37, 41, 41, 41, 43, 43, 43, 47, 47, 47, 47, 47, 53, 53, 53, 53, 53, 53, 59, 59, 59, 59, 61, 61, 61, 61, 67, 67, 67, 67, 67, 71, 71
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,1
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LINKS
| Eric Weisstein's World of Mathematics, Nearest Prime
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EXAMPLE
| Closest primes to 0,1,2,3,4 are 2,2,2,3,3.
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MATHEMATICA
| a[n_] := (np = NextPrime[n]; pp = Prime[PrimePi[np] - 1]; Which[np > 2n-pp, pp, np < 2n-pp, np, True, pp]); a[0] = a[1] = 2; Table[a[n], {n, 0, 71}] (* From Jean-François Alcover, Jul 28 2011 *)
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CROSSREFS
| Related sequences: A023186-A023188, A046929-A046931, A051650, A051652, A051697-A051702, A051728-A051730.
Sequence in context: A055256 A029147 A029097 * A065308 A035680 A103600
Adjacent sequences: A051694 A051695 A051696 * A051698 A051699 A051700
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KEYWORD
| nonn,easy
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com).
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EXTENSIONS
| More terms from James A. Sellers (sellersj(AT)math.psu.edu)
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