A102961 - OEIS

This site is supported by donations to The OEIS Foundation.

A102961

Numbers n such that 2*10^n + 8*R_n - 5 is prime, where R_n = 11...1 is the repunit (A002275) of length n.

0, 1, 2, 7, 28, 73, 295, 494, 598, 2600, 3730, 7549, 15865 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,3`
	COMMENTS	`Also numbers n such that (26*10^n-53)/9 is prime.`
	LINKS	`Makoto Kamada, Factorizations of 288...883.` `Index entries for primes involving repunits.`
	MATHEMATICA	`Do[ If[ PrimeQ[(26*10^n - 53)/9], Print[n]], {n, 0, 10000}]`
	CROSSREFS	`Sequence in context: A137108 A099815 A123363 * A155581 A048504 A092465` `Adjacent sequences: A102958 A102959 A102960 * A102962 A102963 A102964`
	KEYWORD	`more,nonn`
	AUTHOR	`Robert G. Wilson v (rgwv(AT)rgwv.com), Dec 17 2004`
	EXTENSIONS	`Addition of a(13) from Kamada data by Robert Price (pamandbobprice(AT)yahoo.com), Dec 13 2010`

Content is available under The OEIS End-User License Agreement .

Last modified February 15 23:21 EST 2012. Contains 205860 sequences.