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A153769 Numbers n such that 8n-9 is not prime.

%I A153769 #12 Sep 08 2022 08:45:40
%S A153769 0,1,3,6,8,9,12,13,15,16,18,19,21,23,24,27,28,30,32,33,36,37,38,39,41,
%T A153769 42,43,44,45,48,50,51,52,53,54,57,58,60,63,65,66,67,68,69,70,71,72,73,
%U A153769 74,75,78,79,81,83,84,85,86,87,88,89,90
%N A153769 Numbers n such that 8n-9 is not prime.
%H A153769 Vincenzo Librandi, <a href="/A153769/b153769.txt">Table of n, a(n) for n = 1..1000</a>
%e A153769 Distribution of the terms > a(2) in the following triangular array:
%e A153769 *;
%e A153769 3,*;
%e A153769 *,*,*;
%e A153769 *,*,9,*;
%e A153769 *,8,*,*,*;
%e A153769 6,*,*,*,19,*;
%e A153769 *,*,*,18,*,*,*;
%e A153769 *,*,16,*,*,*,33,*;
%e A153769 *,13,*,*,*,32,*,*,*;
%e A153769 9,*,*,*,30,*,*,*,51,*;
%e A153769 *,*,*,27,*,*,*,50,*,*,*;
%e A153769 *,*,23,*,*,*,48,*,*,*,73,*;
%e A153769 *,18,*,*,*,45,*,*,*,72,*,*,*;
%e A153769 12,*,*,*,41,*,*,*,70,*,*,*,99,*; etc.
%e A153769 where * marks the non-integer values of (2*h*k + k + h + 5)/4 with h >= k >= 1. - _Vincenzo Librandi_, Jan 19 2013
%t A153769 lst={};Do[If[!PrimeQ[8*n-9],AppendTo[lst,n]],{n,0, 500}];lst (* _Vincenzo Librandi_, Jul 31 2012 *)
%t A153769 Select[Range[0,100],!PrimeQ[8#-9]&] (* _Harvey P. Dale_, Jun 08 2015 *)
%o A153769 (Magma) [n: n in [0..100]| not IsPrime(8*n-9)]; // _Vincenzo Librandi_, Jul 31 2012
%Y A153769 Cf. A153766.
%K A153769 nonn,easy
%O A153769 1,3
%A A153769 _Vincenzo Librandi_, Jan 01 2009