id:A124485 - OEIS Search Results

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Numbers n such that 2n-1 and 4n-1 are primes.

+0
15

2, 3, 6, 12, 15, 21, 27, 42, 45, 57, 66, 87, 90, 96, 117, 120, 126, 141, 147, 180, 210, 216, 222, 246, 255, 297, 321, 327, 330, 342, 360, 372, 381, 405, 456, 477, 507, 510, 516, 525, 552, 612, 615, 645, 705, 720, 726, 741, 750, 756, 780, 792, 801, 867, 906, 945 (list; graph; listen)

	OFFSET	`1,1`
	MATHEMATICA	`Select[Range[1000], And @@ PrimeQ /@ ({2, 4}# - 1) &] (Chandler*)`
	CROSSREFS	`Cf. A124486-A124492.` `Sequence in context: A110590 A111271 A070926 this_sequence A125867 A032727 A093687` `Adjacent sequences: A124482 A124483 A124484 this_sequence A124486 A124487 A124488`
	KEYWORD	`nonn`
	AUTHOR	`Artur Jasinski (grafix(AT)csl.pl), Nov 04 2006`
	EXTENSIONS	`Extended by Ray Chandler (rayjchandler(AT)sbcglobal.net), Nov 21 2006`

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Last modified November 27 22:38 EST 2009. Contains 167602 sequences.

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