Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #12 Sep 08 2022 08:45:35
%S 67,113,251,389,619,757,941,1033,1171,1217,1447,1493,1723,1861,1907,
%T 1999,2137,2459,2551,2689,3011,3517,3701,3793,3931,4253,4391,4483,
%U 4621,4759,4943,5081,5449,6047,6277,6323,6553,6599,6691,6737,6829,6967,7013,7151
%N Primes congruent to 21 mod 23.
%H Vincenzo Librandi, <a href="/A141925/b141925.txt">Table of n, a(n) for n = 1..1000</a>
%F a(n) ~ 22n log n. - _Charles R Greathouse IV_, Jul 02 2016
%t Select[Range[21,20000,23],PrimeQ] (* _Vladimir Joseph Stephan Orlovsky_, May 18 2011 *)
%o (Magma) [p: p in PrimesUpTo(9000) | p mod 23 eq 21 ]; // _Vincenzo Librandi_, Aug 16 2012
%o (PARI) is(n)=isprime(n) && n%23==21 \\ _Charles R Greathouse IV_, Jul 02 2016
%Y Cf. A000040, A141926.
%K nonn,easy
%O 1,1
%A _N. J. A. Sloane_, Jul 11 2008