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 A357358 #18 Dec 14 2022 09:49:45 %S A357358 6,8,15,20,28,40,48,58,73,88,104,126 %N A357358 Length of the longest induced cycle in the n X n torus grid graph. %C A357358 It is somewhat unclear how a(2) should be defined. If the 2 X 2 torus grid graph is considered to have multiple edges we have a(2) = 2 (a double edge between two nodes makes a 2-cycle), otherwise a(2) = 4. %H A357358 Wikipedia, <a href="https://en.wikipedia.org/wiki/Induced_path">Induced path</a>. %F A357358 a(n) ~ 2*n^2/3. %F A357358 a(n) <= A357359(n) + 1. %e A357358 Longest induced cycles for 3 <= n <= 8: %e A357358 X . X X . . X X . X . X X X X . . . X . X . X . X X . X . X X . X %e A357358 X X . X X . . X . X X . X . X X X . X . X . X X . X . X X . X X . %e A357358 . X X . X X . X X . X . X X . . X . X . X X . X . X X . X X . X . %e A357358 . . X X . X . X X . X . . X X X X . X . X . . X X . X . X X %e A357358 . X X . X . X X X . X . X . X . X X X . X . X X . X %e A357358 . . . X X X . X . X X . X X . X X . X X . %e A357358 . X X . X . X X X . X X . X . %e A357358 . X X . X . X X %Y A357358 Cf. A000937, A297669, A357357, A357359. %K A357358 nonn,more %O A357358 3,1 %A A357358 _Pontus von Brömssen_, Sep 25 2022 %E A357358 a(9)-a(12) from _Elijah Beregovsky_, Dec 11 2022 %E A357358 a(13)-a(14) from _Elijah Beregovsky_, Dec 13 2022