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 A335031 #41 Sep 08 2022 08:46:25
%S A335031 1,2,3,4,6,7,10,11,12,14,15,19,20,22,24,26,27,31,32,34,35,36,39,42,46,
%T A335031 47,50,52,54,55,59,60,64,66,67,70,71,74,75,76,80,87,90,91,92,94,99,
%U A335031 102,104,110,111,112,115,116,119,122,124,126,127,131,132,136
%N A335031 Complement of A334919.
%C A335031 For each term m belonging to this list, 3*m+1 or (3*m+1)/2 is a prime.
%e A335031 1, 2, 3, 4, are terms because for i,j >= 1, number 3*i*j+i+j >= 5, and for i,j >= 2, number 3*i*j-i-j >= 8.
%o A335031 (Magma) [m:m in [1..140]|not exists(a){i:i in [1..m-1]|IsIntegral((m-i)/(1+3*i))} and not exists(b){j:j in [2..m-1]|IsIntegral((m+j)/(-1+3*j)) and (m+j)/(-1+3*j) ge 2}]; // _Marius A. Burtea_, Jun 04 2020
%Y A335031 Cf. A334919.
%K A335031 nonn
%O A335031 1,2
%A A335031 _Davide Rotondo_, May 20 2020