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Search: id:A126243
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| A126243 |
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a(n) = smallest prime number p which is the arithmetic mean of n-th prime < p and n-th prime > p. |
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5
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| 5, 11, 11, 41, 29, 37, 53, 67, 131, 71, 97, 139, 127, 727, 193, 157, 191, 211, 191, 359, 307, 521, 349, 577, 571, 353, 307, 487, 347, 541, 571, 487, 541, 409, 947, 593, 563, 569, 787, 547, 587, 983, 587, 569, 587, 1223, 563, 557, 1213, 569, 563, 1381, 1213
(list; graph; listen)
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OFFSET
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1,1
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LINKS
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Hans Havermann, Table of n, a(n) for n = 1..10000.
Hans Havermann, Plot of n, a(n) for n = 1..10000
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EXAMPLE
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5 is the smallest prime p = prime(n) such that p = (prime(n-1)+prime(n+1))/2 (5 = (3+7)/2).
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MATHEMATICA
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f[n_] := Block[{k = n + 1, p}, While[p = (Prime[k - n] + Prime[k + n])/2; p != Prime[k], k++ ]; p]; Table[f[n], {n, 58}] (*Chandler*)
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CROSSREFS
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Cf. A006562, A119381, A126238-A126243.
Sequence in context: A060846 A113002 A058197 this_sequence A095805 A034596 A122955
Adjacent sequences: A126240 A126241 A126242 this_sequence A126244 A126245 A126246
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KEYWORD
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nonn
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AUTHOR
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Artur Jasinski (grafix(AT)csl.pl), Dec 21 2006
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EXTENSIONS
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Extended by Ray Chandler (rayjchandler(AT)sbcglobal.net), Dec 27 2006
Figure and b-file updated by Hans Havermann, Feb 07 2007
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