A141889 Primes congruent to 4 mod 21.

67, 109, 151, 193, 277, 487, 571, 613, 739, 823, 907, 991, 1033, 1117, 1201, 1327, 1453, 1579, 1621, 1663, 1747, 1789, 1831, 1873, 1999, 2083, 2251, 2293, 2377, 2503, 2671, 2713, 2797, 3049, 3217, 3259, 3301, 3343, 3469, 3511, 3637, 3847, 3889, 3931, 4057

Offset

1,1

Links

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

Formula

a(n) ~ 12n log n. - Charles R Greathouse IV, Jul 03 2016

Mathematica

Select[Range[4, 5000, 21], PrimeQ] (* Vladimir Joseph Stephan Orlovsky, Apr 03 2011*)

Prog

(Magma) [p: p in PrimesUpTo(6000) | p mod 21 eq 4 ]; // Vincenzo Librandi, Aug 16 2012
(PARI) is(n)=isprime(n) && n%21==4 \\ Charles R Greathouse IV, Jul 03 2016

Crossrefs

Cf. A000040, A124826.

Sequence in context: A180521 A139511 A142193 * A289518 A229058 A141925

Adjacent sequences: A141886 A141887 A141888 * A141890 A141891 A141892

Keyword

nonn,easy

Author

N. J. A. Sloane, Jul 11 2008

Status

approved