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A066706
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Numbers k that divide the average of prime(k) and prime(k+1).
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2
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2, 3, 10, 30, 182, 439, 1058, 40086, 40090, 40114, 40120, 100347, 251708, 637328, 637336, 637340, 4124468, 10553440, 10553445, 10553829, 27067138, 179992932, 179993008, 179993012, 179993017, 465769835
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OFFSET
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1,1
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COMMENTS
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Each cluster of candidates is about e (2.71828...) times as large as the previous one. - Robert G. Wilson v, Jan 18 2002
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LINKS
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EXAMPLE
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The average of p(3) = 5 and p(3+1) = 7 is 6, which is divisible by 3; so 3 is a term of the sequence.
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MATHEMATICA
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Select[ Range[10^7], Mod[ (Prime[ # + 1] + Prime[ # ])/2, # ] == 0 & ]
a = 2; b = 3; Do[b = Prime[n + 1]; If[ Mod[(a + b)/2, n] == 0, Print[n]]; a = b, {n, 1, 2*10^9} ]
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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