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 A124041 Numbers k such that 2*k+1, 4*k+1 and 8*k+1 are primes. 7
 9, 39, 165, 219, 249, 309, 414, 534, 639, 765, 1044, 1065, 1089, 1155, 1395, 1509, 1530, 1554, 1590, 1884, 2079, 2115, 2130, 2310, 2319, 2430, 2475, 2709, 2874, 3060, 3105, 3354, 3420, 3684, 3705, 3780, 3819, 4104, 4314, 4554, 4599, 4659, 4869, 5160 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Amiram Eldar, Table of n, a(n) for n = 1..10000 MATHEMATICA Select[3*Range[2000], And @@ PrimeQ /@ ({2, 4, 8}*# + 1) &] (* Ray Chandler, Dec 06 2006 *) CROSSREFS Cf. A005097, A123998, A124412-A124417. Sequence in context: A294845 A124851 A317019 * A264085 A126396 A246065 Adjacent sequences:  A124038 A124039 A124040 * A124042 A124043 A124044 KEYWORD nonn AUTHOR Artur Jasinski, Nov 02 2006 STATUS approved

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Last modified October 28 04:06 EDT 2020. Contains 338048 sequences. (Running on oeis4.)