id:A023302 - OEIS Search Results

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Numbers n such that n remains prime through 4 iterations of function f(x) = 2x + 1.

+0
32

2, 89, 179, 53639, 53849, 61409, 63419, 66749, 126839, 127139, 143609, 167729, 186149, 206369, 254279, 268049, 296099, 340919, 405269, 422069, 446609, 539009, 594449, 607319, 658349, 671249, 725009, 775949, 810539, 810809, 812849, 819509 (list; graph; listen)

	OFFSET	`1,1`
	MATHEMATICA	`Select[Prime[Range[10^44]], PrimeQ[a1=2#+1]&&PrimeQ[a2=2a1+1]&&PrimeQ[a3=2a2+1]&&PrimeQ[a4=2*a3+1] &] (from Vladimir Orlovsky (4vladimir(AT)gmail.com), May 01 2008)`
	CROSSREFS	`Cf. (A005384 and A005385), A007700, A023272, A023330, A057331, A005602.` `Sequence in context: A105268 A139881 A161676 this_sequence A041967 A024239 A076532` `Adjacent sequences: A023299 A023300 A023301 this_sequence A023303 A023304 A023305`
	KEYWORD	`nonn`
	AUTHOR	`David W. Wilson (davidwwilson(AT)comcast.net)`

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

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