A103043 - OEIS

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A103043

Numbers n such that 6*10^n + 7*R_n + 2 is prime, where R_n = 11...1 is the repunit (A002275) of length n.

3, 5, 15, 47, 69, 123, 713, 2316, 6147, 8877, 10704 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,1`
	COMMENTS	`Also numbers n such that (61*10^n+11)/9 is prime.`
	LINKS	`Makoto Kamada, Factorizations of 677...779.` `Index entries for primes involving repunits.`
	MATHEMATICA	`Do[ If[ PrimeQ[(61*10^n + 11)/9], Print[n]], {n, 0, 10000}]`
	CROSSREFS	`Sequence in context: A119472 A018568 A038375 * A018601 A190733 A006394` `Adjacent sequences: A103040 A103041 A103042 * A103044 A103045 A103046`
	KEYWORD	`more,nonn`
	AUTHOR	`Robert G. Wilson v (rgwv(AT)rgwv.com), Jan 18 2005`
	EXTENSIONS	`a(11) from Kamada data by Robert Price (pamandbobprice(AT)yahoo.com), Dec 14 2010`

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Last modified February 15 10:28 EST 2012. Contains 205763 sequences.