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 A072569 Odd interprimes. 24
 9, 15, 21, 39, 45, 69, 81, 93, 99, 105, 111, 129, 165, 195, 205, 217, 225, 231, 279, 309, 315, 351, 363, 381, 393, 399, 405, 441, 453, 459, 465, 473, 483, 489, 495, 501, 515, 615, 625, 645, 667, 675, 687, 705, 723, 741, 747, 759, 765, 771, 803, 825, 855, 861 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS The interprimes (A024675) are those integers that lie at the midpoint between consecutive odd primes. LINKS Harvey P. Dale, Table of n, a(n) for n = 1..1000 Eric Weisstein's World of Mathematics, Interprime MATHEMATICA a = Table[ Prime[n], {n, 2, 200}]; b = {}; Do[d = (a[[n + 1]] - a[[n]])/2; If[ OddQ[ a[[n]] + d], b = Append[b, a[[n]] + d]], {n, 1, 198}]; b Select[Plus @@@ Partition[Table[Prime[n], {n, 2, 100}], 2, 1]/2, OddQ] Select[Mean/@Partition[Prime[Range[2, 200]], 2, 1], OddQ] (* Harvey P. Dale, Jan 22 2019 *) CROSSREFS Odd members of A024675. Sequence is union of A072572 and A072573. Cf. A024675, A072568. Sequence in context: A063174 A338082 A336115 * A072572 A029708 A125215 Adjacent sequences: A072566 A072567 A072568 * A072570 A072571 A072572 KEYWORD nonn AUTHOR Marco Matosic, Jun 24 2002 EXTENSIONS Edited by N. J. A. Sloane and Robert G. Wilson v, Jun 27 2002 STATUS approved

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Last modified July 20 13:32 EDT 2024. Contains 374445 sequences. (Running on oeis4.)