A062607 Numbers k such that 41^k - 40^k is prime.

7, 11, 13, 67, 1051, 9257, 9521, 15077, 21851, 53323, 69427

Offset

1,1

Comments

Terms greater than 1000 are often only strong pseudoprimes.

a(12) > 10^5. - Robert Price, Jul 31 2012

Links

Table of n, a(n) for n=1..11.

Prog

(PARI) is(n)=ispseudoprime(41^n-40^n) \\ Charles R Greathouse IV, Jun 13 2017

Crossrefs

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

Sequence in context: A116442 A191083 A288610 * A018768 A045970 A338597

Adjacent sequences: A062604 A062605 A062606 * A062608 A062609 A062610

Keyword

nonn,hard

Author

Mike Oakes, May 18 2001, May 19 2001

Extensions

a(8)-a(11) (Computed by Adam Marciniec) from Robert Price, Jul 31 2012

Status

approved