A142188 Primes congruent to 13 mod 40.

13, 53, 173, 293, 373, 613, 653, 733, 773, 853, 1013, 1093, 1213, 1373, 1453, 1493, 1613, 1693, 1733, 1933, 1973, 2053, 2213, 2293, 2333, 2693, 3253, 3373, 3413, 3533, 3613, 3733, 3853, 4013, 4093, 4133, 4253, 4373, 4493, 4733, 4813, 4933, 4973, 5333, 5413

Offset

1,1

References

J. V. Uspensky and M. A. Heaslet, Elementary Number Theory, McGraw-Hill, NY, 1939, Exercise n. 2 at p. 346.

Links

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

Formula

a(n) ~ 16n log n. - Charles R Greathouse IV, Jul 03 2016

Mathematica

Select[Prime[Range[2000]], MemberQ[{13}, Mod[#, 40]]&] (* Vincenzo Librandi, Aug 20 2012 *)
(* Alternative: *)
Select[Range[13, 6000, 40], PrimeQ] (* Harvey P. Dale, Feb 15 2025 *)

Prog

(Magma) [p: p in PrimesUpTo(7000) | p mod 40 eq 13]; // Vincenzo Librandi, Aug 20 2012
(PARI) is(n)=isprime(n) && n%40==13 \\ Charles R Greathouse IV, Jul 03 2016

Crossrefs

Cf. A000040.

Sequence in context: A022284 A179549 A139974 * A248409 A206444 A156156

Adjacent sequences: A142185 A142186 A142187 * A142189 A142190 A142191

Keyword

nonn,easy

Author

N. J. A. Sloane, Jul 11 2008

Status

approved