A061240 Prime numbers == 5 (mod 9).

5, 23, 41, 59, 113, 131, 149, 167, 239, 257, 293, 311, 347, 383, 401, 419, 491, 509, 563, 599, 617, 653, 743, 761, 797, 887, 941, 977, 1013, 1031, 1049, 1103, 1193, 1229, 1283, 1301, 1319, 1373, 1409, 1427, 1481, 1499, 1553, 1571, 1607, 1697, 1733, 1787

Offset: 1

Author

Amarnath Murthy, Apr 23 2001

Keywords

• nonn
• easy

Comments

A010888(a(n)) = 5. - Reinhard Zumkeller, Feb 25 2005

Links

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

Crossrefs

Cf. A061237..A061242.

Programs

Magma

[ p: p in PrimesUpTo(2000) | p mod 9 in {5} ]; // Vincenzo Librandi, Dec 25 2010

Mathematica

Select[ Range[ 2500 ], PrimeQ[ # ] && Mod[ #, 9 ] == 5 & ]
Select[Prime[Range[300]],Mod[#,9]==5&] (* Harvey P. Dale, Oct 13 2017 *)

PARI

select(p->p%9==5,primes(1000)) \\ Charles R Greathouse IV, Sep 26 2012

Formula

a(n) ~ 6n log n. - Charles R Greathouse IV, May 14 2025

Extensions

More terms from Robert G. Wilson v, May 10 2001