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 03 2016
MATHEMATICA
Select[Prime[Range[800]], MemberQ[{4}, Mod[#, 27]] &] (* Vincenzo Librandi, Aug 16 2012 *)
PROG
(Magma) [p: p in PrimesUpTo(7000) | p mod 27 eq 4 ]; // Vincenzo Librandi, Aug 16 2012
(PARI) is(n)=isprime(n) && n%27==4 \\ Charles R Greathouse IV, Jul 03 2016
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Jul 11 2008
STATUS
approved