A103051 - OEIS

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A103051

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

1, 2, 4, 17, 25, 32, 50, 74, 173, 1724, 2084, 11398 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,2`
	COMMENTS	`Also numbers n such that (64*10^n+71)/9 is prime.`
	LINKS	`Makoto Kamada, Factorizations of 711...119.` `Index entries for primes involving repunits.`
	MATHEMATICA	`Do[ If[ PrimeQ[(64*10^n + 71)/9], Print[n]], {n, 0, 10000}]`
	CROSSREFS	`Sequence in context: A155951 A118242 A006276 * A095018 A081356 A018269` `Adjacent sequences: A103048 A103049 A103050 * A103052 A103053 A103054`
	KEYWORD	`more,nonn`
	AUTHOR	`Robert G. Wilson v (rgwv(AT)rgwv.com), Jan 19 2005`
	EXTENSIONS	`a(12) from Kamada data by Robert Price (pamandbobprice(AT)yahoo.com), Dec 14 2010`

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Last modified February 17 00:09 EST 2012. Contains 205978 sequences.