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A093794
Numbers n such that 8^n+7^(n-1) is prime.
20
2, 14, 30, 56, 96, 192, 200, 462, 540, 1400, 2756, 9030, 99702
OFFSET
1,1
COMMENTS
a(14) > 10^5. - Robert Price, Feb 18 2016
EXAMPLE
14 is a member since 814+712 = 4494935521511 which is a prime number.
MATHEMATICA
Do[ If[ PrimeQ[8^n + 7^(n - 1)], Print[n]], {n, 4000}]
PROG
(PARI) is(n)=isprime(8^n+7^(n-1)) \\ Charles R Greathouse IV, Feb 17 2017
KEYWORD
nonn
AUTHOR
Herman H. Rosenfeld (herm3(AT)pacbell.net), May 18 2004
EXTENSIONS
More terms from Robert G. Wilson v, Jun 18 2004
a(12)-a(13) from Robert Price, Feb 18 2016
STATUS
approved