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A272345 Numbers n such that 8^n-7^(n-1) is prime. 1
1, 3, 5, 29, 41, 83, 471, 725, 1277, 10271, 15069, 97731 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

a(13) > 10^5.

LINKS

Table of n, a(n) for n=1..12.

EXAMPLE

5 is a member since 8^5 - 7^4 = 32768 - 2401 = 30367 which is a prime number.

MATHEMATICA

Select[Range[0, 100000], PrimeQ[8^# - 7^(# - 1)] &]

PROG

(PARI) is(n)=ispseudoprime(8^n-7^(n-1)) \\ Charles R Greathouse IV, Jun 13 2017

CROSSREFS

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

Sequence in context: A321069 A141578 A327748 * A346659 A067200 A106089

Adjacent sequences:  A272342 A272343 A272344 * A272346 A272347 A272348

KEYWORD

nonn,more

AUTHOR

Robert Price, Apr 26 2016

STATUS

approved

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Last modified December 8 10:14 EST 2021. Contains 349594 sequences. (Running on oeis4.)