cp's OEIS Frontend

A153464 Numbers k such that 4*k+9 is not prime.

%I A153464 #26 Oct 05 2024 09:39:45
%S A153464 0,3,4,6,9,10,12,14,15,17,18,19,21,24,27,28,29,30,31,33,34,36,38,39,
%T A153464 40,42,44,45,48,49,50,51,52,53,54,57,59,60,61,63,64,66,69,70,72,73,74,
%U A153464 75,78,79,80,81,83,84,87,88,89,90,92,93,94,96,99,101,102,104,105
%N A153464 Numbers k such that 4*k+9 is not prime.
%H A153464 Vincenzo Librandi, <a href="/A153464/b153464.txt">Table of n, a(n) for n = 1..1000</a>
%e A153464 Distribution of the terms in the following triangular array:
%e A153464   0;
%e A153464   *,4;
%e A153464   3,*,10;
%e A153464   *,9,*,18;
%e A153464   6,*,17,*,28;
%e A153464   *,14,*,27,*,40;
%e A153464   9,*,24,*,39,*,54;
%e A153464   *,19,*,36,*,53,*,70;
%e A153464   12,*,31,*,50,*,69,*,88;
%e A153464   *,24,*,45,*,66,*,87,*,108;
%e A153464   15,*,38,*,61,*,84,*,107,*,130; etc.
%e A153464 where * marks the non-integer values of (2*h*k + k + h - 4)/2 with h >= k >= 1. - _Vincenzo Librandi_, Jan 14 2013
%t A153464 Select[Range[0, 200], !PrimeQ[4 # + 9] &] (* _Vincenzo Librandi_, Jan 14 2013 *)
%o A153464 (Magma) [n: n in [0..150] | not IsPrime(4*n+9)]; // _Vincenzo Librandi_, Jan 14 2013
%Y A153464 Cf. A111199.
%K A153464 nonn,easy
%O A153464 1,2
%A A153464 _Vincenzo Librandi_, Dec 27 2008
%E A153464 79 added by _R. J. Mathar_, Sep 23 2009
%E A153464 0 added by _Arkadiusz Wesolowski_, Aug 03 2011