A217320 Numbers n such that (13^n - 2^n)/11 is prime.

3, 5, 31, 73, 89, 521, 3943, 8719

Offset

1,1

Comments

All terms are primes.

a(9) > 10^5.

Links

Table of n, a(n) for n=1..8.

Mathematica

Select[ Prime[ Range[1, 100000] ], PrimeQ[ (13^# - 2^#)/11 ]& ]

Prog

(PARI) is(n)=ispseudoprime((13^n-2^n)/11) \\ Charles R Greathouse IV, Jun 06 2017

Crossrefs

Cf. A128028, A016054, A210506.

Sequence in context: A059940 A106893 A175097 * A047105 A136361 A287474

Adjacent sequences: A217317 A217318 A217319 * A217321 A217322 A217323

Keyword

hard,more,nonn

Author

Robert Price, Mar 18 2013

Status

approved