

A171612


Integers n such that (25*10^n)+1 is prime.


0



1, 8, 255, 320, 609, 688, 1436, 3271, 3921, 6520, 19604
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,2


COMMENTS

No others less than 20000.
See Kamada link  primecount.txt for terms, primesize.txt for discovery details including probable or proved primes  search on "25001".


LINKS

Table of n, a(n) for n=1..11.
Makoto Kamada, List of nearrepdigitrelated prime numbers.
Index entries for primes involving repunits.


EXAMPLE

For n=8 we have (25*10^8)+1 = 25*100000000+1 = 2500000000+1 = 2500000001, which is prime.


CROSSREFS

Cf. A056797, A056804, A056805, A056806, A056807
Sequence in context: A213412 A226428 A277421 * A053717 A267250 A034674
Adjacent sequences: A171609 A171610 A171611 * A171613 A171614 A171615


KEYWORD

more,nonn


AUTHOR

Julien Peter Benney (jpbenney(AT)ftml.net), Dec 13 2009


EXTENSIONS

Edited by Ray Chandler, Dec 23 2010


STATUS

approved



