id:A115988 - OEIS Search Results

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Powers of 3 which are the average of two primes p and nextprime(p).

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9, 81, 387420489, 3486784401, 7509466514979724803946715958257547, 147808829414345923316083210206383297601 (list; graph; listen)

	OFFSET	`1,1`
	EXAMPLE	`nextprime(387420479) = 387420499 and (387420479+387420499)/2 = 387420489 = 3^18, so 387420489 belongs to the sequence.`
	CROSSREFS	`Cf. A115986, A115987, A115989.` `Sequence in context: A067216 A076088 A061211 this_sequence A067506 A033119 A033127` `Adjacent sequences: A115985 A115986 A115987 this_sequence A115989 A115990 A115991`
	KEYWORD	`nonn`
	AUTHOR	`Giovanni Resta (g.resta(AT)iit.cnr.it), Feb 10 2006`

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Last modified November 18 20:14 EST 2008. Contains 147244 sequences.