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A273524
Numbers n such that 7^n-6^(n-1) is prime.
0
2, 3, 5, 6, 7, 11, 17, 18, 54, 509, 529, 2526, 3042, 3421, 4485, 13127, 17602, 23825, 27381
OFFSET
1,1
COMMENTS
a(20) > 10^5.
MATHEMATICA
Select[Range[0, 100000], PrimeQ[7^# - 6^(# - 1)] &]
PROG
(PARI) is(n)=ispseudoprime(7^n-6^(n-1)) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
Sequence in context: A362455 A062084 A331394 * A098959 A071251 A077571
KEYWORD
nonn,more
AUTHOR
Robert Price, May 23 2016
STATUS
approved