A142440 - OEIS

%I #11 Aug 03 2024 17:48:45

%S 31,227,521,619,1109,1697,2089,2383,2579,2677,2971,3167,3461,3559,

%T 3853,4049,4441,4637,4931,5323,5519,5813,6793,7283,7577,8263,8753,

%U 9341,9439,9733,9929,10223,10321,10909,11399,11497,11987,12281,12379,12967,13163

%N Primes congruent to 31 mod 49.

%H Vincenzo Librandi, <a href="/A142440/b142440.txt">Table of n, a(n) for n = 1..1000</a>

%F a(n) ~ 42n log n. - _Charles R Greathouse IV_, Jul 03 2016

%t Select[Prime[Range[2500]], MemberQ[{31}, Mod[#,49]] &] (* _Vincenzo Librandi_, Aug 28 2012 *)

%t Select[Range[31,14000,49],PrimeQ] (* _Harvey P. Dale_, Aug 03 2024 *)

%o (Magma) [p: p in PrimesUpTo(17000) | p mod 49 eq 31]; // _Vincenzo Librandi_, Aug 28 2012

%o (PARI) is(n)=isprime(n) && n%49==31 \\ _Charles R Greathouse IV_, Jul 03 2016

%Y Cf. A000040.

%K nonn,easy

%O 1,1

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