Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #9 Jan 29 2023 23:01:37
%S 0,8,94,1004,14864,334536,11546874,629381852,56094263348,
%T 8343512638896,2074276200162230,853966325494701152,
%U 578432462293854136504,646135466408339553958096,1200595044818176185884236342
%N Number of induced paths in the n X n grid graph.
%C Paths of length zero are not counted here.
%C Equivalently, a(n) is the number of snake-like polyominoes in an n X n square. Rotations, reflections and translations are counted separately.
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/GridGraph.html">Grid Graph</a>
%H Wikipedia, <a href="https://en.wikipedia.org/wiki/Induced_path">Induced path</a>
%e The a(2) = 8 induced paths are:
%e O O O . . . . O O O O . . O O O
%e . . O . O O . O O . O O O O . O
%Y Main diagonal of A360199.
%Y Cf. A059525, A297664 (induced cycles), A331968, A331986 (of maximum length), A357516.
%K nonn,more
%O 1,2
%A _Andrew Howroyd_, Jan 29 2023