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A217130 Numbers n such that 7^n + 6 is prime. 10
0, 1, 3, 16, 36, 244, 315, 2577, 9500, 17596, 25551, 32193, 32835, 36504, 75136 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

a(16) > 10^5. - Robert Price, Jan 24 2014

LINKS

Table of n, a(n) for n=1..15.

MATHEMATICA

Select[Range[0, 5000], PrimeQ[7^# + 6] &]

PROG

(PARI) for(n=1, 5000, if(isprime(7^n+6), print1(n", ")))

(MAGMA) /* The code produces the sequence up to 315: */ [n: n in [0..2000] | IsPrime(7^n+6)];

CROSSREFS

Cf. A236371, A217131, A191469, A090669, A096305, A217130, A217132, A152213.

Sequence in context: A076153 A031302 A068415 * A173390 A173891 A066875

Adjacent sequences:  A217127 A217128 A217129 * A217131 A217132 A217133

KEYWORD

nonn

AUTHOR

Vincenzo Librandi, Oct 01 2012

EXTENSIONS

a(9)-a(15) from Robert Price, Jan 24 2014

STATUS

approved

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Last modified July 13 13:48 EDT 2020. Contains 335688 sequences. (Running on oeis4.)