A087872 - OEIS

%I #18 Sep 08 2022 08:45:11

%S 13,421,1013,1861,2381,3613,5101,9941,13613,16381,21013,24421,30013,

%T 34061,47741,52813,60901,82013,99013,106261,168781,218461,223781,

%U 234613,304981,337021,370661,377581,391613,405901,413141,427813,450301,481181

%N Primes of the form (4*k + 3)^2 + (4*k + 2)^2 where k=0,1,2,3,...

%C Primes of the form 32*k^2 + 40*k + 13. - _Vincenzo Librandi_, Dec 12 2011

%H Vincenzo Librandi, <a href="/A087872/b087872.txt">Table of n, a(n) for n = 1..5000</a>

%t Select[Table[32n^2+40n+13,{n,0,800}],PrimeQ] (* _Vincenzo Librandi_, Dec 12 2011 *)

%o (PARI) fourmp1b(n) = { for(x=1,n, z=(4*x+3)^2+(4*x+2)^2; if(isprime(z),print1(z",")) ) }

%o (Magma) [a: n in [0..200] | IsPrime(a) where a is 32*n^2+40*n+13]; // _Vincenzo Librandi_, Dec 12 2011

%Y Cf. A088759.

%K nonn,easy

%O 1,1

%A _Cino Hilliard_, Oct 10 2003

%E More terms from _Ray Chandler_, Oct 19 2003

%E a(1)=13 inserted by _Vincenzo Librandi_, Dec 12 2011

%E Description revised to agree with insertion of new term by _Ray Chandler_, May 21 2017