A103038 - OEIS

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A103038

Numbers n such that 6*10^n + 5*R_n - 4 is prime, where R_n = 11...1 is the repunit (A002275) of length n.

1, 3, 4, 10, 22, 40, 54, 81, 84, 106, 193, 597, 681, 1363, 1876, 4024, 14163, 18733, 20842, 23728, 26419 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,2`
	COMMENTS	`Also numbers n such that (59*10^n-41)/9 is prime.`
	LINKS	`Makoto Kamada, Factorizations of 655...551.` `Index entries for primes involving repunits.`
	MATHEMATICA	`Do[ If[ PrimeQ[(59*10^n - 41)/9], Print[n]], {n, 0, 10000}]`
	CROSSREFS	`Sequence in context: A036649 A109887 A200981 * A143108 A169790 A014009` `Adjacent sequences: A103035 A103036 A103037 * A103039 A103040 A103041`
	KEYWORD	`more,nonn`
	AUTHOR	`Robert G. Wilson v (rgwv(AT)rgwv.com), Jan 18 2005`
	EXTENSIONS	`a(17)-a(21) from Kamada data by Robert Price (pamandbobprice(AT)yahoo.com), Dec 14 2010`

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Last modified February 16 21:51 EST 2012. Contains 205978 sequences.