A085512 - OEIS

The OEIS is supported by the many generous donors to the OEIS Foundation.

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Other ways to Give

A085512

Numbers k such that (89 + 10^(2*k+1))/99 is prime.

0

1, 6, 7, 15, 18, 19, 22, 174, 427, 484, 1702, 2380, 6048, 8257

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

LINKS

Table of n, a(n) for n=1..14.

EXAMPLE

6 is a term because (1/99)*(89 + 10^(2*6+1)) = 101010101011, a prime.

PROG

(PARI) is(n)=isprime((89+10^(2*n+1))/99) \\ Charles R Greathouse IV, Jun 13 2017

CROSSREFS

Sequence in context: A047915 A084382 A315842 * A165767 A292348 A319185

Adjacent sequences: A085509 A085510 A085511 * A085513 A085514 A085515

KEYWORD

nonn

AUTHOR

Jason Earls, Aug 19 2003

EXTENSIONS

a(9)-a(10) from David Wasserman, Feb 03 2005

a(11)-a(12) from L. Joris Perrenet

a(13)-a(14) from Michael S. Branicky, Apr 12 2024

STATUS

approved