A104065 Primes of the form 7^k + 4.

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

Offset

1,1

Links

Table of n, a(n) for n=1..9.

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

Sequence in context: A149527 A201180 A109546 * A212304 A018545 A028349

Adjacent sequences: A104062 A104063 A104064 * A104066 A104067 A104068

Keyword

nonn

Author

Roger L. Bagula, Mar 02 2005

Extensions

Initial 5 from Vincenzo Librandi, Dec 10 2010

Status

approved