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 A124514 Numbers k for which 2*k-1, 4*k-1, 8*k-1, 16*k-1, 32*k-1, 64*k-1 and 128*k-1 are primes. 8
 561330, 1082115, 1164735, 5128905, 5154945, 6157350, 7015155, 7072770, 9549960, 11551830, 12088065, 14421825, 18544365, 19099920, 21194760, 24580050, 25392720, 26277285, 31400085, 34359030, 42932385, 44087025, 47915595 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Amiram Eldar, Table of n, a(n) for n = 1..1000 MATHEMATICA Select[15*Range[3200000], And @@ PrimeQ /@ ({2, 4, 8, 16, 32, 64, 128}*# - 1) &] (* Ray Chandler, Nov 22 2006 *) apQ[n_]:=AllTrue[NestList[2#&, 2n, 6]-1, PrimeQ]; Select[15*Range[ 32*10^5], apQ] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Dec 08 2019 *) CROSSREFS Cf. A006254, A124485, A124493, A124494, A124017, A125113, A124515, A124516. Sequence in context: A206194 A250534 A234207 * A100416 A151878 A273236 Adjacent sequences: A124511 A124512 A124513 * A124515 A124516 A124517 KEYWORD nonn AUTHOR Artur Jasinski, Nov 04 2006 STATUS approved

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Last modified May 29 19:17 EDT 2023. Contains 363042 sequences. (Running on oeis4.)