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A274693 Numbers n such that 4^n + 3^(n+1) is prime. 0
1, 2, 4, 5, 9, 10, 12, 17, 18, 29, 30, 40, 58, 82, 113, 129, 164, 192, 252, 524, 624, 766, 977, 1742, 2208, 2440, 3052, 4742, 5480, 16572, 17501 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

a(32) > 10^5.

LINKS

Table of n, a(n) for n=1..31.

EXAMPLE

5 is a member since 4^5 + 3^6 = 1024 + 729 = 1753 which is a prime number.

MATHEMATICA

Select[Range[0, 100000], PrimeQ[4^# + 3^(# + 1)] &]

PROG

(PARI) lista(nn) = for(n=1, nn, if(ispseudoprime(4^n + 3^(n+1)), print1(n, ", "))); \\ Altug Alkan, Jul 02 2016

(MAGMA) [n: n in [1..700] | IsPrime(4^n + 3^(n+1))]; // Vincenzo Librandi, Jul 03 2016

CROSSREFS

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

Sequence in context: A036795 A307563 A289175 * A024618 A089221 A347877

Adjacent sequences:  A274690 A274691 A274692 * A274694 A274695 A274696

KEYWORD

nonn,more

AUTHOR

Robert Price, Jul 02 2016

STATUS

approved

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Last modified September 26 05:07 EDT 2021. Contains 347664 sequences. (Running on oeis4.)