%I #5 Feb 26 2023 23:10:06

%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="http://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

%O 1,2

%A _Andrew Howroyd_, Feb 26 2023