id:A023272 - OEIS Search Results

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Numbers n such that n remains prime through 3 iterations of function f(x) = 2x + 1.

+0
32

2, 5, 89, 179, 359, 509, 1229, 1409, 2699, 3539, 6449, 10589, 11549, 11909, 12119, 17159, 19709, 19889, 22349, 26189, 27479, 30389, 43649, 53639, 53849, 55229, 57839, 60149, 61409, 63419, 66749, 71399, 74699, 75329, 82499, 87539, 98369, 101399 (list; graph; listen)

	OFFSET	`1,1`
	MATHEMATICA	`Select[Prime[Range[10^34]], PrimeQ[a1=2#+1]&&PrimeQ[a2=2a1+1]&&PrimeQ[a3=2a2+1] &] (from Vladimir Orlovsky (4vladimir(AT)gmail.com), May 01 2008)`
	CROSSREFS	`Cf. (A005384 and A005385), A007700, A023302, A023330, A057331, A005602.` `Sequence in context: A120798 A048187 A082431 this_sequence A057978 A093308 A162569` `Adjacent sequences: A023269 A023270 A023271 this_sequence A023273 A023274 A023275`
	KEYWORD	`nonn`
	AUTHOR	`David W. Wilson (davidwwilson(AT)comcast.net)`

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Last modified November 27 14:50 EST 2009. Contains 167570 sequences.

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