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 A153235 #18 Sep 08 2022 08:45:39 %S A153235 1,4,6,7,10,11,13,14,16,17,19,21,22,25,26,28,30,31,34,35,36,37,39,40, %T A153235 41,42,43,46,48,49,50,51,52,55,56,58,61,63,64,65,66,67,68,69,70,71,72, %U A153235 73,76,77,79,81,82,83,84,85,86,87,88,91,94,95,96,97,98,99,100,101 %N A153235 Numbers n such that 8*n+7 is not prime. %H A153235 Vincenzo Librandi, <a href="/A153235/b153235.txt">Table of n, a(n) for n = 1..1000</a> %e A153235 Distribution of the terms in the following triangular array: %e A153235 *; %e A153235 1,*; %e A153235 *,*,*; %e A153235 *,*,7,*; %e A153235 *,6,*,*,*; %e A153235 4,*,*,*,17,*; %e A153235 *,*,*,16,*,*,*; %e A153235 *,*,14,*,*,*,31,*; %e A153235 *,11,*,*,*,30,*,*,*; %e A153235 7,*,*,*,28,*,*,*,49,*: %e A153235 *,*,*,25,*,*,*,48,*,*,*; %e A153235 *,*,21,*,*,*,46,*,*,*,71,*; etc. %e A153235 where * marks the non-integer values of (2*h*k + k + h - 3)/4 with h >= k >= 1. - _Vincenzo Librandi_, Jan 15 2013 %t A153235 Select[Range[0, 200], !PrimeQ[8 # + 7] &] (* _Vincenzo Librandi_, Jan 12 2013 *) %o A153235 (Magma) [n: n in [0..110] | not IsPrime(8*n+7)]; // _Vincenzo Librandi_, Jan 12 2013 %Y A153235 Cf. A139487. %K A153235 nonn,easy %O A153235 1,2 %A A153235 _Vincenzo Librandi_, Dec 21 2008