A265484 Numbers n such that 36^n - 6^n - 1 is prime.

1, 2, 3, 4, 24, 63, 81, 92, 165, 232, 236, 591, 669, 1343, 2973, 3630, 5600, 7019, 17169, 31945, 52172

Offset

1,2

Comments

For n = 1, 2, 3, 4, 24 the corresponding primes are 29, 1259, 46439, 1678319, 22452257707354557235348829785471057919.

a(22) > 10^5. - Robert Price, Jan 06 2020

Links

Table of n, a(n) for n=1..21.

Example

4 is in the sequence because 36^4 - 6^4 - 1 = 1678319 is prime.

Mathematica

Select[Range[1000], PrimeQ[36^# - 6^# - 1] &]

Prog

(Magma) [n: n in [0..300] | IsPrime(36^n-6^n-1)];
(PARI) for(n=1, 1e3, if(ispseudoprime(36^n - 6^n - 1), print1(n, ", "))) \\ Altug Alkan, Dec 12 2015

Crossrefs

Cf. similar sequences listed in A265481.

Sequence in context: A233344 A329566 A329532 * A000336 A287433 A235041

Adjacent sequences: A265481 A265482 A265483 * A265485 A265486 A265487

Keyword

nonn,more

Author

Vincenzo Librandi, Dec 12 2015

Extensions

a(14)-a(18) from Ray Chandler, Sep 25 2019

a(18) corrected and a(19)-a(21) added by Robert Price, Jan 06 2020

Status

approved