

A062586


Numbers n such that 20^n  19^n is prime.


1




OFFSET

1,1


COMMENTS

Terms n > 1000 may correspond to (unproven) strong pseudoprimes 20^n  19^n.


LINKS

Table of n, a(n) for n=1..9.
Top probable primes of the form 20^p19^p


PROG

(PARI) is(n)=ispseudoprime(20^n19^n) \\ Charles R Greathouse IV, Jun 12 2017


CROSSREFS

Cf. A000043, A057468, A059801, A059802, A062572A062666.
Sequence in context: A084167 A267143 A234797 * A301641 A067710 A197912
Adjacent sequences: A062583 A062584 A062585 * A062587 A062588 A062589


KEYWORD

nonn,hard


AUTHOR

Mike Oakes, May 18 2001, May 19 2001


EXTENSIONS

Three more terms (18661, 79621 and 81649) found by JeanLouis Charton in February and March 2011 corresponding to probable primes with 24279, 103590 and 106228 digits.
Edited by M. F. Hasler, Sep 16 2013


STATUS

approved



