A142421 Primes congruent to 9 mod 49.

107, 401, 499, 1087, 1283, 1381, 1871, 2459, 2557, 2753, 2851, 3733, 3929, 4027, 4517, 4909, 5399, 5693, 5791, 5987, 6379, 6673, 6869, 6967, 7457, 8731, 9221, 9319, 9613, 9907, 10103, 10691, 10789, 11083, 11279, 11867, 12161, 12553, 13043, 13337, 13729

Offset

1,1

Links

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

Formula

a(n) ~ 42n log n. - Charles R Greathouse IV, Jul 03 2016

Mathematica

Select[Prime[Range[1700]], Mod[#, 49]==9&]  (* Harvey P. Dale, Apr 20 2011 *)
Select[Prime[Range[2500]], MemberQ[{9}, Mod[#, 49]] &] (* Vincenzo Librandi, Aug 27 2012 *)
Select[Range[9, 14000, 49], PrimeQ] (* Harvey P. Dale, Nov 04 2023 *)

Prog

(Magma) [p: p in PrimesUpTo(16000) | p mod 49 eq 9]; // Vincenzo Librandi, Aug 27 2012
(PARI) is(n)=isprime(n) && n%49==9 \\ Charles R Greathouse IV, Jul 03 2016

Crossrefs

Cf. A000040.

Sequence in context: A106948 A139989 A059699 * A183847 A142696 A142775

Adjacent sequences: A142418 A142419 A142420 * A142422 A142423 A142424

Keyword

nonn,easy

Author

N. J. A. Sloane, Jul 11 2008

Status

approved