A102998 - OEIS

This site is supported by donations to The OEIS Foundation.

A102998

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

1, 4, 10, 12, 13, 40, 76, 123, 501, 648, 3541, 4002, 4228, 5271, 7432, 27306 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,2`
	COMMENTS	`Also numbers n such that (44*10^n-53)/9 is prime.`
	LINKS	`Makoto Kamada, Factorizations of 488...883.` `Index entries for primes involving repunits.`
	MATHEMATICA	`Do[ If[ PrimeQ[(44*10^n - 53)/9], Print[n]], {n, 0, 10000}]`
	CROSSREFS	`Sequence in context: A078005 A092428 A170943 * A071179 A155475 A023693` `Adjacent sequences: A102995 A102996 A102997 * A102999 A103000 A103001`
	KEYWORD	`more,nonn`
	AUTHOR	`Robert G. Wilson v (rgwv(AT)rgwv.com), Jan 17 2005`
	EXTENSIONS	`Addition of a(16) from Kamada data by Robert Price (pamandbobprice(AT)yahoo.com), Dec 12 2010`

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

Last modified February 15 17:46 EST 2012. Contains 205835 sequences.