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 A124491 Numbers n such that 2n-1, 4n-1, 6n-1, 8n-1, 10n-1, 12n-1, 14n-1 and 16n-1 are primes. 2

%I #10 Oct 11 2019 11:06:48

%S 1447110,30020760,32261985,121012185,203937090,546020475,546037695,

%T 837344865,1140530160,2517567255,2664703335,2841691440,2896212165,

%U 3000108405,3190108740,5204790360,5744351970,6872932605,7090912185

%N Numbers n such that 2n-1, 4n-1, 6n-1, 8n-1, 10n-1, 12n-1, 14n-1 and 16n-1 are primes.

%C All terms are multiples of 105. - _Harvey P. Dale_, May 08 2019

%t k = 0;inc = 3*5*7;While[k < 7200000000,k += inc;While[Nand @@ PrimeQ /@ ({2, 4, 6, 8, 10, 12, 14, 16}*k - 1), k += inc];Print[k];];(* _Ray Chandler_, Nov 21 2006 *)

%t Select[Range[105,7091*10^6,105],AllTrue[2*Range[8]#-1,PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* _Harvey P. Dale_, May 08 2019 *)

%Y Cf. A124485-A124492.

%K nonn

%O 1,1

%A _Artur Jasinski_, Nov 04 2006

%E Corrected and extended by _Ray Chandler_, Nov 21 2006

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Last modified April 23 16:40 EDT 2024. Contains 371916 sequences. (Running on oeis4.)