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A093717 Numbers n such that 4^n+3^(n-1) is prime. 19
1, 2, 3, 4, 6, 8, 10, 12, 15, 19, 27, 30, 32, 34, 43, 48, 51, 72, 88, 106, 906, 963, 1328, 1336, 1611, 1664, 2680, 3122, 3267, 5323, 6499, 7870, 32836, 37846, 38456, 41912, 45238, 51991, 63530, 68704 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
a(41) > 10^5. - Robert Price, Apr 11 2016
LINKS
EXAMPLE
19 is a member since 4^19 + 3^18 = 2388583837526729, which is a prime number.
MATHEMATICA
Select[Range[1000], PrimeQ[4^# + 3^(# - 1)] &]
PROG
(PARI) is(n)=isprime(4^n+3^(n-1)) \\ Charles R Greathouse IV, Feb 17 2017
CROSSREFS
Sequence in context: A347656 A238616 A302833 * A359754 A330899 A325796
KEYWORD
nonn
AUTHOR
Herman H. Rosenfeld (herm3(AT)pacbell.net), May 17 2004
EXTENSIONS
More terms from Robert G. Wilson v, Jun 18 2004
a(30)-a(40) from Robert Price, Apr 11 2016
STATUS
approved

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Last modified September 1 22:05 EDT 2024. Contains 375597 sequences. (Running on oeis4.)