A103082 - OEIS

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A103082

Numbers n such that 8*10^n + 4*R_n + 5 is prime, where R_n = 11...1 is the repunit (A002275) of length n.

1, 4, 13, 37, 46, 106, 139, 469, 5695 (list; graph; refs; listen; history; text; internal format)

	OFFSET	`1,2`
	COMMENTS	`Also numbers n such that (76*10^n+41)/9 is prime.`
	LINKS	`Table of n, a(n) for n=1..9.` `Makoto Kamada, Factorizations of 844...449.` `Index entries for primes involving repunits.`
	MATHEMATICA	`Do[ If[ PrimeQ[(76*10^n + 41)/9], Print[n]], {n, 0, 10000}]`
	CROSSREFS	`Sequence in context: A222425 A222189 A003727 * A048474 A054761 A080145` `Adjacent sequences: A103079 A103080 A103081 * A103083 A103084 A103085`
	KEYWORD	`more,nonn`
	AUTHOR	`Robert G. Wilson v, Jan 19 2005`
	STATUS	`approved`

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Last modified June 20 00:15 EDT 2013. Contains 226416 sequences.