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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
1447110, 30020760, 32261985, 121012185, 203937090, 546020475, 546037695, 837344865, 1140530160, 2517567255, 2664703335, 2841691440, 2896212165, 3000108405, 3190108740, 5204790360, 5744351970, 6872932605, 7090912185 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

All terms are multiples of 105. - Harvey P. Dale, May 08 2019

LINKS

Table of n, a(n) for n=1..19.

MATHEMATICA

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 *)

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 *)

CROSSREFS

Cf. A124485-A124492.

Sequence in context: A156621 A108841 A124490 * A205892 A186533 A224974

Adjacent sequences:  A124488 A124489 A124490 * A124492 A124493 A124494

KEYWORD

nonn

AUTHOR

Artur Jasinski, Nov 04 2006

EXTENSIONS

Corrected and extended by Ray Chandler, Nov 21 2006

STATUS

approved

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Last modified December 4 09:51 EST 2021. Contains 349485 sequences. (Running on oeis4.)