OFFSET
1,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
FORMULA
a(n) ~ 30n log n. - Charles R Greathouse IV, Jul 03 2016
MATHEMATICA
Select[Range[20, 20000, 31], PrimeQ] (* Vladimir Joseph Stephan Orlovsky, Apr 30 2011 *)
Select[Prime[Range[1400]], Mod[#, 31]==20&] (* Harvey P. Dale, Jul 30 2020 *)
PROG
(Magma) [p: p in PrimesUpTo(12000) | p mod 31 eq 20 ]; // Vincenzo Librandi, Aug 17 2012
(PARI) is(n)=isprime(n) && n%31==20 \\ Charles R Greathouse IV, Jul 03 2016
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Jul 11 2008
STATUS
approved