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Primes of the form 8*k^2 + 7.
3

%I #13 Oct 13 2024 02:42:07

%S 7,79,5839,7207,8719,18439,25999,28807,41479,45007,48679,93319,109519,

%T 121039,145807,180007,209959,294919,313639,342799,415879,472399,

%U 583207,720007,734479,778759,935719,952207,1216807,1331719,1391119,1431439

%N Primes of the form 8*k^2 + 7.

%H Vincenzo Librandi, <a href="/A201704/b201704.txt">Table of n, a(n) for n = 1..5000</a>

%t Select[Table[8n^2+7,{n,0,200}],PrimeQ]

%o (Magma) [a: n in [0..500] | IsPrime(a) where a is 8*n^2+7];

%Y Cf. A121068 (corresponding k).

%K nonn,easy

%O 1,1

%A _Vincenzo Librandi_, Dec 04 2011