id:A031441 - OEIS Search Results

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a(0) = 3; for n > 0, a(n) is the greatest prime factor of PreviousPrime(a(n-1))*a(n-1)-1 where PreviousPrime(prime(k))=prime(k-1).

+0
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3, 5, 7, 17, 11, 19, 23, 109, 17, 11, 19, 23, 109, 17, 11, 19, 23, 109, 17, 11, 19, 23, 109, 17, 11, 19, 23, 109, 17, 11, 19, 23, 109, 17, 11, 19, 23, 109, 17, 11, 19, 23, 109, 17, 11, 19, 23, 109, 17, 11, 19, 23, 109, 17, 11, 19, 23, 109, 17, 11, 19, 23, 109, 17, 11, 19, 23 (list; graph; listen)

	OFFSET	`0,1`
	EXAMPLE	`To get a(3) we compute PreviousPrime(7)=5, 5*7-1=34, greatest prime factor of 34 is 17, so a(3)=17.`
	CROSSREFS	`Cf. A034970, A031442.` `Sequence in context: A078683 A099863 A112092 this_sequence A078150 A114265 A110358` `Adjacent sequences: A031438 A031439 A031440 this_sequence A031442 A031443 A031444`
	KEYWORD	`nonn,easy,nice`
	AUTHOR	`Yasutoshi Kohmoto (zbi74583(AT)boat.zero.ad.jp)`
	EXTENSIONS	`More terms from James A. Sellers (sellersj(AT)math.psu.edu)`

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Last modified November 25 20:09 EST 2009. Contains 167514 sequences.

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