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A274711 Numbers n such that 5^n + 4^(n+1) is prime. 0
0, 2, 6, 34, 282, 3662, 87206 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

a(8) > 10^5.

LINKS

Table of n, a(n) for n=1..7.

EXAMPLE

6 is a member since 5^6 + 4^7 = 15625 + 16384 = 32009 which is a prime number.

MATHEMATICA

Select[Range[0, 100000], PrimeQ[5^# + 4^(# + 1)] &]

PROG

(PARI) lista(nn) = for(n=0, nn, if(ispseudoprime(5^n + 4^(n+1)), print1(n, ", "))); \\ Altug Alkan, Jul 03 2016

CROSSREFS

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

Sequence in context: A325296 A052878 A168362 * A076863 A191742 A181082

Adjacent sequences:  A274708 A274709 A274710 * A274712 A274713 A274714

KEYWORD

nonn,more

AUTHOR

Robert Price, Jul 03 2016

STATUS

approved

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Last modified October 23 12:19 EDT 2019. Contains 328345 sequences. (Running on oeis4.)