id:A072920 - OEIS Search Results

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Sum(k=1,n, A034693(k)).

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1, 2, 4, 5, 7, 8, 12, 14, 16, 17, 19, 20, 24, 26, 28, 29, 35, 36, 46, 48, 50, 51, 53, 56, 60, 62, 66, 67, 69, 70, 80, 83, 85, 88, 90, 91, 95, 100, 102, 103, 105, 106, 110, 112, 116, 117, 123, 125, 129, 131, 133, 134, 136, 138, 144, 146, 150, 151, 163, 164, 170, 175 (list; graph; listen)

	OFFSET	`1,2`
	FORMULA	`a(n) appears to be asymptotic to (zeta(2)-1)nLog(n) where zeta(2)-1 = Pi^2/6-1 = 0.6449.....Example: a(10^5)/10^5/log(10^5) = 0.6449(1......`
	PROGRAM	`(PARI) To generate A034693(n): a(n)=if(n<0, 0, s=1; while(isprime(s*n+1)==0, s++); prime(s))`
	CROSSREFS	`Adjacent sequences: A072917 A072918 A072919 this_sequence A072921 A072922 A072923` `Sequence in context: A014554 A114147 A025516 this_sequence A107899 A032924 A005125`
	KEYWORD	`nonn`
	AUTHOR	`Benoit Cloitre (benoit7848c(AT)orange.fr), Aug 11 2002`

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Last modified October 10 20:39 EDT 2008. Contains 144831 sequences.

AT&T Labs Research