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A124486 Numbers n such that 2n-1, 4n-1 and 6n-1 are primes. 1
2, 3, 12, 15, 42, 45, 87, 117, 120, 147, 210, 330, 477, 507, 612, 705, 780, 792, 945, 1002, 1065, 1170, 1275, 1347, 1470, 1680, 1695, 1797, 1902, 2175, 2187, 2205, 2460, 2472, 2667, 3057, 3087, 4047, 4137, 4257, 4530, 4740, 4770, 5082, 5157, 5295, 5775 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..47.

MATHEMATICA

Select[Range[6000], And @@ PrimeQ /@ ({2, 4, 6}*# - 1) &] (*Chandler*)

CROSSREFS

Cf. A124485-A124492.

Sequence in context: A090512 A076175 A067780 * A260908 A123761 A181121

Adjacent sequences:  A124483 A124484 A124485 * A124487 A124488 A124489

KEYWORD

nonn

AUTHOR

Artur Jasinski, Nov 04 2006

EXTENSIONS

Extended by Ray Chandler, Nov 21 2006

STATUS

approved

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Last modified August 29 08:06 EDT 2015. Contains 261188 sequences.