cp's OEIS Frontend

A153236 Numbers n such that 8*n + 3 is not prime.

%I A153236 #14 Sep 08 2022 08:45:39
%S A153236 3,4,6,9,11,12,14,15,18,19,21,23,24,25,27,29,30,32,33,34,36,37,39,40,
%T A153236 42,44,45,46,48,49,50,51,53,54,56,57,59,60,63,64,66,67,69,72,74,75,76,
%U A153236 78,79,81,83,84,87,88,89,90,91,93,94,95,96,97
%N A153236 Numbers n such that 8*n + 3 is not prime.
%H A153236 Vincenzo Librandi, <a href="/A153236/b153236.txt">Table of n, a(n) for n = 1..1000</a>
%e A153236 Distribution of the terms in the following triangular array:
%e A153236 *;
%e A153236 *,*;
%e A153236 *,4,*;
%e A153236 3,*,*,*;
%e A153236 *,*,*,12,*;
%e A153236 *,*,11,*,*,*;
%e A153236 *,9,*,*,*,24,*;
%e A153236 6,*,*,*,23,*,*,*;
%e A153236 *,*,*,21,*,*,*,40,*;
%e A153236 *,*,18,*,*,*,39,*,*,*;
%e A153236 *,14,*,*,*,37,*,*,*,60,*;
%e A153236 9,*,*,*,34,*,*,*,59,*,*,*; etc.
%e A153236 where * marks the non-integer values of (2*h*k + k + h - 1)/4 with h >= k >= 1. - _Vincenzo Librandi_, Jan 15 2013
%t A153236 Select[Range[0, 200], !PrimeQ[8 # + 3] &] (* _Vincenzo Librandi_, Jan 12 2013 *)
%o A153236 (Magma) [n: n in [0..110] | not IsPrime(8*n+3)]; // _Vincenzo Librandi_, Jan 12 2013
%Y A153236 Cf. A007520, A005124, A139487.
%K A153236 nonn,easy
%O A153236 1,1
%A A153236 _Vincenzo Librandi_, Dec 21 2008