A229542 Numbers n such that (19^n - 2^n)/17 is prime.

11, 19, 79, 631, 1787, 2011, 2381, 20219, 49523

Offset

1,1

Comments

All terms are primes.

a(10) > 2*10^5.

Links

Table of n, a(n) for n=1..9.

Mathematica

Select[ Prime[ Range[1, 100000] ], PrimeQ[ (19^# - 2^#)/17 ]& ]

Prog

(PARI) is(n)=ispseudoprime((19^n-2^n)/17) \\ Charles R Greathouse IV, Jun 13 2017

Crossrefs

Cf. A128032, A225955, A225807, A006035.

Sequence in context: A335410 A106231 A107637 * A039365 A103201 A199338

Adjacent sequences: A229539 A229540 A229541 * A229543 A229544 A229545

Keyword

nonn,hard,more

Author

Robert Price, Sep 25 2013

Status

approved