A138931 Primes of the form (10^n-3^n)/7.

13, 139, 14251, 1428571428571428571364245156301286091

Offset

1,1

Comments

The next term is too large to include here.

Links

Table of n, a(n) for n=1..4.

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

Adjacent sequences: A138928 A138929 A138930 * A138932 A138933 A138934

Keyword

nonn

Author

Vladimir Joseph Stephan Orlovsky, May 16 2008

Status

approved