3146000domain: NAppears in sequencesNumber of n X 7 0..1 arrays avoiding 0 0 1 and 0 1 1 horizontally and 0 0 1 and 1 0 1 vertically.at n=9A208141Number of free treelike midpoint-free polycubes of size n, identifying rotations and reflections.at n=27A368031