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 A066706 Numbers k that divide the average of prime(k) and prime(k+1). 2
 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 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Each cluster of candidates is about e (2.71828...) times as large as the previous one. - Robert G. Wilson v, Jan 18 2002 LINKS EXAMPLE 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. MATHEMATICA 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} ] CROSSREFS Sequence in context: A338593 A270363 A131764 * A209003 A080022 A192913 Adjacent sequences:  A066703 A066704 A066705 * A066707 A066708 A066709 KEYWORD nonn AUTHOR Joseph L. Pe, Jan 14 2002 EXTENSIONS More terms from Robert G. Wilson v, Jan 16 2002 More terms from Robert G. Wilson v, Jan 18 2002 STATUS approved

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Last modified September 21 21:32 EDT 2021. Contains 347605 sequences. (Running on oeis4.)