OFFSET
1,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
FORMULA
a(n) ~ 18n log n. - _Charles R Greathouse IV_, Jul 02 2016
MATHEMATICA
Select[Prime[Range[800]], MemberQ[{1}, Mod[#, 27]] &] (* _Vincenzo Librandi_, Aug 16 2012 *)
Select[Range[1, 6000, 27], PrimeQ] (* _Harvey P. Dale_, Jan 16 2023 *)
PROG
(Magma) [p: p in PrimesUpTo(7000) | p mod 27 eq 1 ]; // _Vincenzo Librandi_, Aug 16 2012
(PARI) is(n)=isprime(n) && n%27==1 \\ _Charles R Greathouse IV_, Jul 02 2016
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
_N. J. A. Sloane_, Jul 11 2008
STATUS
approved