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%I #15 Sep 08 2022 08:45:39
%S 1,4,5,7,8,10,13,15,16,19,20,21,22,25,27,28,29,30,31,32,33,34,35,36,
%T 37,39,40,43,45,46,49,50,52,54,55,56,57,58,59,60,61,64,65,67,70,71,72,
%U 73,74,75,76,78,79,80,82,83,84,85,87,88,90,91,92,94,95,96,97,98,99,100
%N Numbers n such that 16*n+5 is not prime.
%H Vincenzo Librandi, <a href="/A153327/b153327.txt">Table of n, a(n) for n = 1..1000</a>
%e Distribution of the terms in the following triangular array:
%e *;
%e *,*;
%e 1,*,*;
%e *,*,*,*;
%e *,*,*,*,*,;
%e *,*,*,7,*,*;
%e *,*,*,*,10,*,*;
%e *,5,*,*,*,*,*,*;
%e *,*,8,*,*,*,*,*,*;
%e *,*,*,*,*,*,*,22,*,*;
%e 4,*,*,*,*,*,*,*,27*,*;
%e *,*,*,*,*,20,*,*,*,*,*,*;
%e *,*,*,*,*,*,25,*,*,*,*,*,*; etc.
%e where * marks the non-integer values of (2*h*k + k + h - 2)/8 with h >= k >= 1. - _Vincenzo Librandi_, Jan 17 2013
%t Select[Range[100], !PrimeQ[16# + 5]&] (* _Harvey P. Dale_, Oct 03 2011 *)
%o (Magma) [n: n in [0..150] | not IsPrime(16*n + 5)]; // _Vincenzo Librandi_, Jan 12 2013
%Y Cf. A127590.
%K nonn,easy
%O 1,2
%A _Vincenzo Librandi_, Dec 23 2008
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