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A155945 Numbers n such that 24*n + 13 is not prime. 1

%I

%S 3,5,8,10,12,13,18,19,20,21,23,24,26,28,32,33,37,38,39,40,43,47,48,49,

%T 52,53,54,55,56,58,61,62,63,65,68,71,73,75,76,78,79,81,82,83,86,87,88,

%U 89,90,91,93,96,98,100

%N Numbers n such that 24*n + 13 is not prime.

%H Vincenzo Librandi, <a href="/A155945/b155945.txt">Table of n, a(n) for n = 1..1000</a>

%e Distribution of the terms in the following triangular array:

%e *;

%e *,*;

%e *,*,*;

%e *,*,*,*;

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

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

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

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

%e *,*,5,*,*,*,*,*,*;

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

%e *,*,*,*,10,*,*,*,*,*,*;

%e *,*,*,*,*,13,*,*,*,*,*,*; etc.

%e where * marks the non-integer values of (2*h*k + k + h - 6)/12 with h >= k >= 1. - _Vincenzo Librandi_, Jan 15 2013

%t Select[Range[0, 100], !PrimeQ[24 # + 13] &] (* _Vincenzo Librandi_, Oct 15 2012 *)

%o (MAGMA) [n: n in [0..100] |not IsPrime(24*n + 13)]; // _Vincenzo Librandi_, Oct 15 2012

%Y Cf. A139529, A139530.

%K nonn,easy

%O 1,1

%A _Vincenzo Librandi_, Jan 31 2009

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Last modified December 1 01:37 EST 2021. Contains 349426 sequences. (Running on oeis4.)