A062593 Numbers k such that 27^k - 26^k is prime.

2, 13, 157, 43117

Offset

1,1

Comments

Terms > 1000 are often only strong pseudoprimes.

a(5) > 10^5. - Robert Price, Aug 12 2012.

Links

Table of n, a(n) for n=1..4.

Prog

(PARI) is(n)=ispseudoprime(27^n-26^n) \\ Charles R Greathouse IV, Jun 12 2017

Crossrefs

Cf. A000043, A057468, A059801, A059802, A062572-A062666.

Sequence in context: A366012 A297408 A316701 * A347051 A291140 A192563

Adjacent sequences: A062590 A062591 A062592 * A062594 A062595 A062596

Keyword

nonn,hard

Author

Mike Oakes, May 18 2001, May 19 2001

Extensions

a(4) from Robert Price, Aug 12 2012

Status

approved