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Primes congruent to 21 mod 44.
1

%I #9 Sep 08 2022 08:45:36

%S 109,197,241,373,461,593,769,857,1033,1297,1429,1693,1913,2089,2221,

%T 2309,2441,2617,2749,2837,2969,3541,3673,3761,4157,4201,4289,4421,

%U 4597,4729,4817,4861,4993,5081,5477,5521,5653,5741,6269,6577,6709,6841,7193,7237

%N Primes congruent to 21 mod 44.

%H Vincenzo Librandi, <a href="/A142301/b142301.txt">Table of n, a(n) for n = 1..1000</a>

%F a(n) ~ 20n log n. - _Charles R Greathouse IV_, Jul 03 2016

%t Select[Prime[Range[2500]],MemberQ[{21},Mod[#,44]]&] (* _Vincenzo Librandi_, Aug 25 2012 *)

%o (Magma) [p: p in PrimesUpTo(8000) | p mod 44 eq 21]; // _Vincenzo Librandi_, Aug 25 2012

%o (PARI) is(n)=isprime(n) && n%44==21 \\ _Charles R Greathouse IV_, Jul 03 2016

%Y Cf. A000040.

%K nonn,easy

%O 1,1

%A _N. J. A. Sloane_, Jul 11 2008