A103027 - OEIS

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A103027

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

2, 3, 5, 11, 12, 23, 75, 101, 122, 173, 647, 2015, 2684, 11700, 19625 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,1`
	COMMENTS	`Also numbers n such that (55*10^n+17)/9 is prime.`
	LINKS	`Makoto Kamada, Factorizations of 611...113.` `Index entries for primes involving repunits.`
	MATHEMATICA	`Do[ If[ PrimeQ[(55*10^n + 17)/9], Print[n]], {n, 0, 10000}]`
	CROSSREFS	`Sequence in context: A087583 A111214 A066159 * A093902 A100475 A187921` `Adjacent sequences: A103024 A103025 A103026 * A103028 A103029 A103030`
	KEYWORD	`more,nonn`
	AUTHOR	`Robert G. Wilson v (rgwv(AT)rgwv.com), Jan 18 2005`
	EXTENSIONS	`Addition of a(14)-a(15) from Kamada data by Robert Price (pamandbobprice(AT)yahoo.com), Dec 12 2010`

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Last modified February 17 04:46 EST 2012. Contains 205985 sequences.