A103063 - OEIS

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A103063

Numbers n such that 7*10^n + 6*R_n - 5 is prime, where R_n = 11...1 is the repunit (A002275) of length n.

1, 2, 6, 25, 69, 253, 300, 384, 434, 721, 822, 883, 2192, 2649, 3441, 3445, 8028, 11655 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,2`
	COMMENTS	`Also numbers n such that (23*10^n-17)/3 is prime.`
	LINKS	`Makoto Kamada, Factorizations of 766...661.` `Index entries for primes involving repunits.`
	MATHEMATICA	`Do[ If[ PrimeQ[(23*10^n - 17)/3], Print[n]], {n, 0, 10000}]`
	CROSSREFS	`Sequence in context: A086591 A173609 A073545 * A030228 A066317 A027104` `Adjacent sequences: A103060 A103061 A103062 * A103064 A103065 A103066`
	KEYWORD	`more,nonn`
	AUTHOR	`Robert G. Wilson v (rgwv(AT)rgwv.com), Jan 19 2005`
	EXTENSIONS	`a(18) from Kamada data by Robert Price (pamandbobprice(AT)yahoo.com), Dec 14 2010`

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Last modified February 18 00:14 EST 2012. Contains 206085 sequences.