A102962 - OEIS

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A102962

Numbers n such that 2*10^n + 8*R_n - 1 is prime, where R_n = 11...1 is the repunit (A002275) of length n.

3, 6, 18, 69, 443, 449, 455, 2459, 4745, 7973, 14249 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,1`
	COMMENTS	`Also numbers n such that (26*10^n-17)/9 is prime.`
	LINKS	`Makoto Kamada, Factorizations of 288...887.` `Index entries for primes involving repunits.`
	MATHEMATICA	`Do[ If[ PrimeQ[(26*10^n - 17)/9], Print[n]], {n, 0, 10000}]`
	CROSSREFS	`Sequence in context: A173109 A165200 A178789 * A076510 A038060 A135504` `Adjacent sequences: A102959 A102960 A102961 * A102963 A102964 A102965`
	KEYWORD	`more,nonn`
	AUTHOR	`Robert G. Wilson v (rgwv(AT)rgwv.com), Dec 17 2004`
	EXTENSIONS	`Addition of a(11) from Kamada data by Robert Price (pamandbobprice(AT)yahoo.com), Dec 13 2010`

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Last modified February 16 17:48 EST 2012. Contains 205939 sequences.