A141890 Primes congruent to 5 mod 21.

5, 47, 89, 131, 173, 257, 383, 467, 509, 593, 677, 719, 761, 887, 929, 971, 1013, 1097, 1181, 1223, 1307, 1433, 1559, 1601, 1811, 1979, 2063, 2273, 2357, 2399, 2441, 2609, 2693, 2777, 2819, 2861, 2903, 3323, 3407, 3449, 3491, 3533, 3617, 3659, 3701, 3911

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[5, 5000, 21], PrimeQ] (* Vladimir Joseph Stephan Orlovsky, Apr 03 2011*)
Select[Prime[Range[600]], Mod[#, 21]==5&] (* Harvey P. Dale, Jan 30 2021 *)

Prog

(Magma) [p: p in PrimesUpTo(6000) | p mod 21 eq 5 ]; // Vincenzo Librandi, Aug 16 2012
(PARI) is(n)=isprime(n) && n%21==5 \\ Charles R Greathouse IV, Jul 03 2016

Crossrefs

Cf. A000040, A124826.

Sequence in context: A060392 A196160 A136088 * A056248 A126575 A229613

Adjacent sequences: A141887 A141888 A141889 * A141891 A141892 A141893

Keyword

nonn,easy

Author

N. J. A. Sloane, Jul 11 2008

Status

approved