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A265484 Numbers n such that 36^n - 6^n - 1 is prime. 1
1, 2, 3, 4, 24, 63, 81, 92, 165, 232, 236, 591, 669, 1343, 2973, 3630, 5600, 7019, 17169, 31945, 52172 (list; graph; refs; listen; history; text; internal format)
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

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Last modified April 8 09:44 EDT 2020. Contains 333313 sequences. (Running on oeis4.)