%I #10 Sep 08 2022 08:45:39

%S 2,3,6,7,9,12,15,16,17,18,20,21,22,23,24,25,27,28,30,32,33,36,37,38,

%T 39,42,44,45,47,48,50,51,52,53,54,56,57,58,60,61,62,63,64,65,66,67,69,

%U 71,72,75,76,77,78,79,81,82,83,84,85,86,87,88,90,92,93,94

%N Numbers n such that 16*n+3 is not prime.

%H Vincenzo Librandi, <a href="/A153348/b153348.txt">Table of n, a(n) for n = 1..1000</a>

%e Triangle begins:

%e *;

%e *,*;

%e *,2,*;

%e *,*,*,*;

%e *,*,*,6,*;

%e *,*.*,*,*,*;

%e *,*,*,*,*,12,*;

%e 3,*,*,*,*,*,*,*;

%e *,*,*,*,*,*,*,20,*;

%e *,*,9,*,*,*,*,*,*,*;

%e *,7,*,*,*,*,*,*,*,30,*;

%e *,*,*,*,17,*,*,*,*,*,*,*;

%e where * marks the non-integer values of (2*h*k + k + h - 1)/8 with h >= k >= 1.

%t Select[Range[200], !PrimeQ[16*# + 3]&] (* _Vincenzo Librandi_, Jan 13 2013 *)

%o (Magma) [n: n in [0..150] | not IsPrime(16*n + 3)]; // _Vincenzo Librandi_, Jan 13 2013

%Y Cf. A092022.

%K nonn,easy

%O 1,1

%A _Vincenzo Librandi_, Dec 24 2008