Frieze group 3 of 7, p1m1: Conway's sidle, point group m, 2 operations per period, orbifold *∞∞. Motifs back to back, then front to front, along the row.
Molecular point groups with their operations and character tables, the 230 space groups with a cell builder, and the 17 wallpaper and 7 frieze groups drawn live. The tool needs JavaScript, and WebGL2 for the 3D views; these are the pages it offers: