This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A153219 #18 Sep 08 2022 08:45:39 %S A153219 3,7,8,13,14,18,19,21,23,27,28,30,33,35,38,40,41,42,43,47,48,49,52,53, %T A153219 56,58,59,63,64,66,68,70,73,74,77,78,79,81,83,84,85,87,88,91,92,93 %N A153219 Numbers n such that 6*n + 7 is not prime. %C A153219 One less than the associated entry in A046954. - _R. J. Mathar_, Jan 05 2011 %H A153219 Vincenzo Librandi, <a href="/A153219/b153219.txt">Table of n, a(n) for n = 1..1000</a> %e A153219 Distribution of the terms in the following triangular array: %e A153219 *; %e A153219 *,3; %e A153219 *,*,7; %e A153219 *,*,*,*; %e A153219 *,8,*,*,19; %e A153219 *,*,14,*,*,27; %e A153219 *,*, *,*,*, *,*; %e A153219 *,13,*,*,30,*,*,47; %e A153219 *,*,21,*,*,40,*,*,59; %e A153219 *,*,*, *,*, *,*,*, *,*; %e A153219 *,18,*,*,41,*,*,64,*,*,87; %e A153219 *,*,28,*,*,53,*,*,78,*,*,103; etc. %e A153219 where * marks the non-integer values of (2*h*K + k + h - 3)/3 with h >= k >= 1. - _Vincenzo Librandi_, Jan 15 2013 %t A153219 Select[Range[0, 200], !PrimeQ[6 # + 7] &] (* _Vincenzo Librandi_, Jan 12 2013 *) %o A153219 (Magma) [n: n in [0..110] | not IsPrime(6*n+7)]; // _Vincenzo Librandi_, Jan 12 2013 %Y A153219 Cf. A153218. %K A153219 nonn,easy %O A153219 1,1 %A A153219 _Vincenzo Librandi_, Dec 21 2008