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%I #14 Sep 08 2022 08:45:35
%S 113,547,733,857,919,1229,1291,1601,1663,1787,1973,2221,2531,2593,
%T 2903,3089,3461,3709,3833,4019,4391,4639,5011,5197,5507,5569,5693,
%U 5879,6871,7057,7243,8111,8297,8669,8731,9041,9103,9227,9413,9661,10343,10529,11087
%N Primes congruent to 20 mod 31.
%H Vincenzo Librandi, <a href="/A142024/b142024.txt">Table of n, a(n) for n = 1..1000</a>
%F a(n) ~ 30n log n. - _Charles R Greathouse IV_, Jul 03 2016
%t Select[Range[20,20000,31],PrimeQ] (* _Vladimir Joseph Stephan Orlovsky_, Apr 30 2011 *)
%t Select[Prime[Range[1400]],Mod[#,31]==20&] (* _Harvey P. Dale_, Jul 30 2020 *)
%o (Magma) [p: p in PrimesUpTo(12000) | p mod 31 eq 20 ]; // _Vincenzo Librandi_, Aug 17 2012
%o (PARI) is(n)=isprime(n) && n%31==20 \\ _Charles R Greathouse IV_, Jul 03 2016
%Y Cf. A000040, A142005, A142006, A142023.
%K nonn,easy
%O 1,1
%A _N. J. A. Sloane_, Jul 11 2008