id:A103032 - OEIS Search Results

Search: id:A103032

Displaying 1-1 of 1 results found.

page 1

Numbers n such that 6*10^n + 3*R_n - 2 is prime, where R_n = 11...1 is the repunit (A002275) of length n.

+0
3

1, 2, 4, 7, 18, 19, 23, 24, 34, 41, 56, 64, 84, 149, 272, 755, 1272, 2398, 2686, 4800, 5198, 6217, 8737 (list; graph; listen)

	OFFSET	`1,2`
	COMMENT	`Also numbers n such that (19*10^n-7)/3 is prime.`
	LINKS	`Makoto Kamada, Factorizations of 633...331.` `Index entries for primes involving repunits.`
	MATHEMATICA	`Do[ If[ PrimeQ[(19*10^n - 7)/3], Print[n]], {n, 0, 10000}]`
	CROSSREFS	`Sequence in context: A027238 A076894 A047871 this_sequence A101569 A101805 A145777` `Adjacent sequences: A103029 A103030 A103031 this_sequence A103033 A103034 A103035`
	KEYWORD	`more,nonn`
	AUTHOR	`Robert G. Wilson v (rgwv(AT)rgwv.com), Jan 18 2005`

page 1

Search completed in 0.002 seconds

Last modified November 21 21:21 EST 2009. Contains 167310 sequences.