A142008 Primes congruent to 4 mod 31.

97, 283, 593, 1151, 1213, 1399, 1523, 1709, 2081, 2143, 2267, 2887, 3011, 3259, 3631, 4003, 4127, 4561, 4871, 4933, 5119, 5801, 5987, 6173, 6359, 6421, 6607, 6793, 6917, 7103, 7351, 7537, 7723, 8219, 8467, 8839, 8963, 9397, 9521, 9769, 10079, 10141, 10513

Offset: 1

Author

N. J. A. Sloane, Jul 11 2008

Keywords

• nonn
• easy

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A000040, A142005, A142006.

Programs

Magma

[ p: p in PrimesUpTo(30000) | p mod 31 eq 4 ]; // Vincenzo Librandi, Apr 20 2011

Mathematica

Select[Range[4,20000,31],PrimeQ] (* Vladimir Joseph Stephan Orlovsky, Apr 20 2011 *)
Select[Prime[Range[1500]],Mod[#,31]==4&] (* Harvey P. Dale, Sep 21 2021 *)

PARI

is(n)=isprime(n) && n%31==4 \\ Charles R Greathouse IV, Jul 03 2016

Formula

a(n) ~ 30n log n. - Charles R Greathouse IV, Jul 03 2016