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 A153351 #16 Sep 08 2022 08:45:39 %S A153351 1,2,4,6,7,8,9,10,12,13,14,16,17,18,19,20,22,24,25,26,28,29,30,31,32, %T A153351 34,35,36,37,38,39,40,41,42,43,44,46,48,49,50,52,54,55,56,58,59,60,61, %U A153351 62,64,66,67,68,69,70,72,73,74,75,76,78,79,80,82,83,84,85,86,87,88,89,90 %N A153351 Numbers n such that 7*n+2 is not prime. %H A153351 Vincenzo Librandi, <a href="/A153351/b153351.txt">Table of n, a(n) for n = 1..1000</a> %e A153351 Distribution of the odd terms in the following triangular array: %e A153351 1; %e A153351 *,*; %e A153351 *,*,*; %e A153351 *,*,*,*; %e A153351 *,*,*,*,17; %e A153351 *,9,*,*,*,*; %e A153351 *,*,*,19,*,*,*; %e A153351 7,*,*,*,*,*,*,41; %e A153351 *,*,*,*,*,35,*,*,*; %e A153351 *,*,*,*,*,*,*,*,*,*; %e A153351 *,*,*,*,*,*,49,*,*,*,*; %e A153351 *,*,*,*,39,*,*,*,*,*,*,89; %e A153351 *,19,*,*,*,*,*,*,73,*,*,*,*; etc. %e A153351 where * marks the non-integer values of (4*h*k + 2*k + 2*h - 1)/7 with h >= k >= 1. - _Vincenzo Librandi_, Jan 17 2013 %t A153351 Select[Range[200], !PrimeQ[7 # + 2] &] (* _Vincenzo Librandi_, Jan 13 2013 *) %o A153351 (Magma) [n: n in [0..150] | not IsPrime(7*n + 2)]; // _Vincenzo Librandi_, Jan 13 2013 %Y A153351 Cf. A105772. %K A153351 nonn,easy %O A153351 1,2 %A A153351 _Vincenzo Librandi_, Dec 24 2008 %E A153351 Erroneous comment deleted by _N. J. A. Sloane_, Jun 23 2010