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A138931
Primes of the form (10^n-3^n)/7.
0
13, 139, 14251, 1428571428571428571364245156301286091
OFFSET
1,1
COMMENTS
The next term is too large to include here.
MATHEMATICA
a={}; Do[p=(10^n-3^n)/7; If[PrimeQ[p], AppendTo[a, p]], {n, 1, 25^2}]; a
Select[Table[(10^n-3^n)/7, {n, 50}], PrimeQ] (* Harvey P. Dale, Dec 18 2018 *)
CROSSREFS
Cf. A128026.
Sequence in context: A266630 A186506 A051639 * A157160 A263480 A210766
KEYWORD
nonn
AUTHOR
STATUS
approved