A062608 Numbers k such that 42^k - 41^k is prime.

2, 3, 5, 47, 67, 103

Offset: 1

Author

Mike Oakes, May 18 2001, May 19 2001

Keywords

• nonn
• hard
• more

Comments

Terms greater than 1000 are often only strong pseudoprimes.

No further terms up to 5000. - Harvey P. Dale, Mar 13 2011

a(7) > 10^5. - Robert Price, Sep 21 2012

Crossrefs

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

Programs

Mathematica

Select[Range[5000], PrimeQ[42^# - 41^#] &] (* Harvey P. Dale, Mar 13 2011 *)

PARI

is(n)=ispseudoprime(42^n-41^n) \\ Charles R Greathouse IV, Jun 12 2017