A103090 - OEIS

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A103090

Numbers n such that 8*10^n + 7*R_n - 4 is prime, where R_n = 11...1 is the repunit (A002275) of length n.

1, 7, 36, 99, 325, 1227, 9261, 9414, 11115, 25149, 43212 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,2`
	COMMENTS	`Also numbers n such that (79*10^n-43)/9 is prime.`
	LINKS	`Makoto Kamada, Factorizations of 877...773.` `Index entries for primes involving repunits.`
	MATHEMATICA	`Do[ If[ PrimeQ[(79*10^n - 43)/9], Print[n]], {n, 0, 10000}]`
	CROSSREFS	`Sequence in context: A018199 A063168 A163683 * A184246 A097554 A055221` `Adjacent sequences: A103087 A103088 A103089 * A103091 A103092 A103093`
	KEYWORD	`more,nonn`
	AUTHOR	`Robert G. Wilson v (rgwv(AT)rgwv.com), Jan 19 2005`
	EXTENSIONS	`a(9)-a(11) from Kamada data by Robert Price (pamandbobprice(AT)yahoo.com), Dec 14 2010`

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Last modified February 15 09:54 EST 2012. Contains 205763 sequences.