Shown with a cast-on count of 35 stitches.  

• Rows 1, 3, 11, and 13 (RS): P1, *k1, p1, k12, p1, k1, p1, repeat from *.
• Row 2: *P1, k1, p1, k12, p1, k1, repeat from * to last st, p1.
• Rows 4 and 6: *P1, k2, k4, p4, k4, k2, repeat from * to last st, p1.
• Rows 5 and 15: P1, *k1, p1, k4, 2/2 LC, k4, p1, k1, p1, repeat from *.
• Rows 7 and 17: P1, *k1, p1, k2, 2/2 RC, 2/2 LC, k2, p1, k1, p1, repeat from *.
• Row 8: *P1, k2, k2, p2, k4, p2, k2, k2, repeat from * to last st, p1.
• Rows 9 and 19: P1, *k1, p1, 2/2 RC, k4, 2/2 LC, p1, k1, p1, repeat from *.
• Rows 10, 12, and 20: *P1, k2, p2, k8, p2, k2, repeat from * to last st, p1.
• Rows 14 and 16: *P1, k2, p2, k2, p4, k2, p2, k2, repeat from * to last st, p1.
• Row 18: *P1, k2, p4, k4, p4, k2, repeat from * to last st, p1.
• Repeat rows 11-20.