Shown with a cast-on count of 10 stitches.  

• Rows 1 and 3 (WS): P1, k2, p2, k2, p2, p1.
• Row 2: K1, k2, p2, k2, p2, k1.
• Row 4: K1, M1Lp, k2, p2, k2, p2, k1 (11 sts).
• Row 5: P1, k2, p2, k2, p2, k1, p1.
• Row 6: K1, M1Lp, p1, k2, p2, k2, p2, k1 (12 sts).
• Row 7: P1, k2, p2, k2, p2, k2, p1.
• Row 8: K1, M1L, p2, M1R, *k2, p2, repeat from * to last st, k1 (14 sts).
• Row 9: P1, k2, p2, k2, p3, k2, p2.
• Row 10: K1, M1L, k1, p2, k1, M1R, *k2, p2, repeat from * to last st, k1 (16 sts).
• Row 11: P1, k2, p2, k2, p4, k2, p3.
• Row 12: K1, M1Lp, k2, p2, k2, M1Rp, *k2, p2, repeat from * to last st, k1 (18 sts).
• Row 13: P1, k2, p2, k2, p2, k1, p2, k2, p2, k1, p1.
• Row 14: K1, M1Lp, p1, k2, p2, k2, p1, M1Rp, *k2, p2, repeat from * to last st, k1 (20 sts).
• Row 15: P1, k2, p2, k2, p2, k2, p2, k2, p2, k2, p1.
• Row 16: K1, p2, k2, p2, k2, p2, M1R, *k2, p2, repeat from * to last st, k1 (21 sts).
• Row 17: P1, k2, p2, k2, p3, k2, p2, k2, p2, k2, p1.
• Row 18: K1, p2, k2, p2, k2, p2, k1, M1R, *k2, p2, repeat from * to last st, k1 (22 sts).
• Row 19: P1, k2, p2, k2, p4, k2, p2, k2, p2, k2, p1.
• Row 20: K1, p2, k2, p2, k2, p2, k2, M1Rp, *k2, p2, repeat from * to last st, k1 (23 sts).
• Row 21: P1, k2, p2, k2, p2, k1, p2, k2, p2, k2, p2, k2, p1.