login

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”).

A108506
Integers n such that 10^n-59 is prime.
4
2, 3, 4, 8, 20, 38, 95, 248, 263, 303, 304, 410, 438, 548, 688, 1074, 1575, 8364, 9910, 15910, 37344
OFFSET
1,1
COMMENTS
Certified primality of numbers corresponding to terms 410, 438, 548, 688, 1074 and 1575 with Primo. - Ryan Propper, Jul 08 2005
No other terms <40000.
See Kamada link - primecount.txt for terms, primesize.txt for discovery details including probable or proved primes - search on "99941".
EXAMPLE
8 is a member because: n = 8 gives 10^8-59 = 100000000-59 = 99999941, which is prime.
KEYWORD
more,nonn
AUTHOR
Julien Peter Benney (jpbenney(AT)ftml.net), Jul 06 2005
EXTENSIONS
a(18)-a(20) from Kamada data by Robert Price, Dec 10 2010
a(21) by Robert Price, Dec 16 2010
Edited by Ray Chandler, Dec 23 2010
STATUS
approved