A124490 Numbers n such that 2n-1, 4n-1, 6n-1, 8n-1, 10n-1, 12n-1 and 14n-1 are primes.

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

Offset: 1

Author

Artur Jasinski, Nov 04 2006

Keywords

• nonn

Crossrefs

Cf. A124485-A124492.

Programs

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 *)

Extensions

Extended by Ray Chandler, Nov 21 2006

More terms from Harvey P. Dale, May 17 2018