符号付偶数交点数列 { 16, -10, 14, -18, 12, -4, 8, 2, -6 } 始点座標 { (r,-90,-r,-18r), (r,-90,-r,-4r), (r,-90,-r,-2r) } 射影交点座標 { (rK,-135,0,0), (rK,135,0,0), (0,0,0,0), (r,-90,r/2,-r), (rK,45,0,0), (r,90,0,0), (r,0,0,0), (r,180,0,0), …