%I #6 Feb 16 2025 08:34:04
%S 1,3,7,12,19,26,36,46,59,72,87,102,120,138,159
%N Maximum number of vertices in an induced tree in the n X n grid graph.
%H Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/GridGraph.html">Grid Graph</a>.
%F a(n) >= A331968(n).
%e a(4) = 12:
%e O O O O
%e O O
%e O O O
%e O O O
%Y Main diagonal of A360920.
%Y Cf. A331968, A357357, A360919 (maximum induced trees).
%K nonn,more,changed
%O 1,2
%A _Andrew Howroyd_, Feb 26 2023