A093717 - OEIS

A093717

Numbers n such that 4^n+3^(n-1) is prime.

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

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OFFSET

1,2

COMMENTS

a(41) > 10^5. - Robert Price, Apr 11 2016

LINKS

Table of n, a(n) for n=1..40.

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

Cf. A082103, A093793, A093765, A096185, A093794, A093795, A096186.

Sequence in context: A347656 A238616 A302833 * A359754 A330899 A325796

Adjacent sequences: A093714 A093715 A093716 * A093718 A093719 A093720

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