%I #22 Aug 12 2023 00:30:39
%S 1,1,2,4,12,34,125,450,1780,7021,28521,115553,472578,1927634,7890893,
%T 32221475,131812746,538059836,2198986587,8970624060,36628143111,
%U 149328243327,609238673619
%N Number of free linear polycubes of size n, identifying rotations and reflections.
%C Linear polycubes have two end points with one neighbor, the remaining cubes all have two neighbors.
%C Identifying rotations but not reflections gives A363201.
%C The fixed version is A118339.
%H Arthur O'Dwyer, <a href="https://quuxplusone.github.io/blog/2022/12/08/polyomino-snakes/">Polyomino strips, snakes, and ouroboroi</a>, 2022.
%Y Cf. A304196 (tree-like polycubes), A363208, A363209, A363210.
%K nonn,more
%O 1,3
%A _Joerg Arndt_ and _Márk Péter Légrádi_, May 21 2023
%E a(17)-a(22) from Arthur O'Dwyer added by _Andrey Zabolotskiy_, Jun 07 2023
%E a(23) added by _Arthur O'Dwyer_, Aug 11 2023