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A269227 Numbers n such that 7^n + 6^(n + 1) is prime. 0
0, 1, 4, 5, 12, 16, 27, 87, 252, 1052, 1691, 3237, 3669, 16140, 17072, 27932, 70811 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

a(18) > 10^5.

LINKS

Table of n, a(n) for n=1..17.

MATHEMATICA

Select[Range[0, 100000], PrimeQ[7^# + 6^(# + 1)] &]

PROG

(MAGMA) [n: n in [0..500] | IsPrime(7^n+6^(n+1))]; // Vincenzo Librandi, Jul 12 2016

(PARI) is(n)=ispseudoprime(7^n+6^(n+1)) \\ Charles R Greathouse IV, Jun 13 2017

CROSSREFS

Cf. A093765.

Sequence in context: A137619 A115375 A212114 * A103650 A131116 A261692

Adjacent sequences:  A269224 A269225 A269226 * A269228 A269229 A269230

KEYWORD

nonn,more

AUTHOR

Robert Price, Jul 11 2016

STATUS

approved

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Last modified October 21 14:27 EDT 2019. Contains 328301 sequences. (Running on oeis4.)