A062588 Numbers k such that 22^k - 21^k is prime.

2, 127, 877

Offset

1,1

Comments

All terms are prime.

No other terms less than 10^5. - Robert Price, May 28 2012

Links

Table of n, a(n) for n=1..3.

Prog

(PARI) is(n)=ispseudoprime(22^n-21^n) \\ Charles R Greathouse IV, Jun 12 2017

Crossrefs

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

Sequence in context: A274123 A141928 A343184 * A125634 A075596 A092832

Adjacent sequences: A062585 A062586 A062587 * A062589 A062590 A062591

Keyword

nonn,hard,bref,more

Author

Mike Oakes, May 18 2001, May 19 2001

Status

approved