A165567 - OEIS

%I #7 Sep 08 2022 08:45:48

%S 19,43,89,229,593,701,1223,1483,1889,2699,3319,4463,4751,6553,7019,

%T 11779,11933,13859,19699,23003,28201,31123,33409,39901,41039,44549,

%U 49139,51679,63901,81001,83843,87151,92233,97459,102829,104651,112573,131839,136501

%N Primes of the form (p^2 - 1)/8 - p, where p is also a prime.

%C The associated p are in A165566.

%H Vincenzo Librandi, <a href="/A165567/b165567.txt">Table of n, a(n) for n = 1..1000</a>

%e p=17 generates a(1) = 19 = (17^2-1)/8 -17. p=23 generates a(2) = 43 = (23^2-1)/8-23.

%t Select[Table[(p^2 - 1)/8 - p, {p, Prime[Range[4, 200]]}], PrimeQ] (* _Vincenzo Librandi_, Oct 12 2012 *)

%o (Magma) [a: p in PrimesInInterval(6, 1200) | IsPrime(a) where a is (p^2 - 1) div 8 - p ]; // _Vincenzo Librandi_, Oct 12 2012

%Y Cf. A165566.

%K nonn,easy

%O 1,1

%A _Vincenzo Librandi_, Sep 22 2009

%E Sequence extended by _R. J. Mathar_, Oct 16 2009