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A272781 Numbers n such that 6^n-5^(n+1) is prime. 0
9, 14, 32, 48, 78, 85, 108, 134, 834, 1701, 2275, 3103, 5795, 10307, 17243, 24045, 31085, 32613, 40014 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(20) > 10^5.

LINKS

Table of n, a(n) for n=1..19.

EXAMPLE

9 is a member since 6^9 - 5^10 = 10077696 - 9765625 = 312071 which is a prime number.

MATHEMATICA

Select[Range[0, 100000], PrimeQ[6^# - 5^(# + 1)] &]

PROG

(PARI) is(n)=ispseudoprime(6^n-5^(n+1)) \\ Charles R Greathouse IV, Jun 13 2017

CROSSREFS

Cf. A093713, A082103, A093717, A093793, A096185, A093794, A093795, A096186, A271883, A271884.

Sequence in context: A104812 A329751 A093021 * A229543 A175201 A066793

Adjacent sequences:  A272778 A272779 A272780 * A272782 A272783 A272784

KEYWORD

nonn,more

AUTHOR

Robert Price, May 06 2016

STATUS

approved

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Last modified September 28 17:43 EDT 2020. Contains 337393 sequences. (Running on oeis4.)