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 A124490 Numbers n such that 2n-1, 4n-1, 6n-1, 8n-1, 10n-1, 12n-1 and 14n-1 are primes. 1
 1447110, 2623005, 4095000, 4339335, 6975780, 9080190, 12382755, 19455975, 20322960, 30020760, 32261985, 54202995, 62014155, 63196350, 66383520, 71369340, 94571295, 121012185, 124225920, 162780660, 177109380, 196068180, 223888665, 303047745, 310143960 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Table of n, a(n) for n=1..25. MATHEMATICA Select[3*5*7*Range[2000000], And @@ PrimeQ /@ ({2, 4, 6, 8, 10, 12, 14}*# - 1) &] (* Ray Chandler, Nov 21 2006 *) pr7Q[n_]:=AllTrue[2*Range[7]n-1, PrimeQ]; Select[105*Range[3*10^6], pr7Q] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, May 17 2018 *) CROSSREFS Cf. A124485-A124492. Sequence in context: A210629 A156621 A108841 * A124491 A205892 A186533 Adjacent sequences: A124487 A124488 A124489 * A124491 A124492 A124493 KEYWORD nonn AUTHOR Artur Jasinski, Nov 04 2006 EXTENSIONS Extended by Ray Chandler, Nov 21 2006 More terms from Harvey P. Dale, May 17 2018 STATUS approved

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Last modified February 27 16:21 EST 2024. Contains 370378 sequences. (Running on oeis4.)