A104065 - OEIS

A104065

Primes of the form 7^k + 4.

5, 11, 53, 347, 16811, 823547, 40353611, 678223072853, 27368747340080916347

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OFFSET

1,1

LINKS

MATHEMATICA

a = Delete[Union[Flatten[Table[If [PrimeQ[7^n + 3 + 1] == True, 7^n + 3 + 1, 0], {n, 1, 400}]]], 1]

Select[7^Range[0, 30]+4, PrimeQ] (* Harvey P. Dale, Jul 31 2021 *)

CROSSREFS

KEYWORD

nonn

AUTHOR

EXTENSIONS

Initial 5 from Vincenzo Librandi, Dec 10 2010

STATUS

approved