A274135 - OEIS

A274135

Numbers n such that 6^n + 5^(n+1) is prime.

1, 4, 6, 9, 12, 15, 18, 21, 34, 36, 75, 102, 231, 256, 309, 513, 748, 3789, 12378, 36378

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OFFSET

1,2

COMMENTS

a(21) > 10^5.

LINKS

MATHEMATICA

Select[Range[0, 100000], PrimeQ[6^n + 5^(n + 1)] &]

PROG

(PARI) is(n)=ispseudoprime(6^n + 5^(n+1)) \\ Charles R Greathouse IV, Jun 10 2016

(PFGW) ABC2 6^$a + 5^($a+1)

a: from 1 to 100000

CROSSREFS

KEYWORD

nonn,more

AUTHOR

Robert Price, Jun 10 2016

STATUS

approved