131019domain: NAppears in sequencesNumber of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, 0, 1), (1, -1, -1), (1, 0, 1), (1, 1, 0)}.at n=9A150434Number of subsets of {1..n} that contain n but do not form a finite arithmetic progression.at n=18A389921