Shown with a cast-on count of 85 stitches.  

• Row 1 (RS): K2tog, k4, yo, k2tog tbl, k15, *k2tog, yo, k16, repeat from * to last 8 sts, k2tog, yo, k4, k2tog tbl (multiple of 18 sts, plus 29).
• Rows 2, 4, 6, 8, 10, 12, 14, 16, 18, and 20: Knit.
• Row 3: K2tog, k4, *yo, k2tog tbl, k5, k2tog, yo, k6, k2tog, yo, k1, repeat from * to last 5 sts, k3, k2tog tbl (multiple of 18 sts, plus 9).
• Row 5: K2tog, k4, *yo, k2tog tbl, k3, k2tog, yo, k1, yo, k2tog tbl, k3, k2tog, yo, k3, repeat from * to last 3 sts, k1, k2tog tbl (multiple of 18 sts, plus 7).
• Row 7: K2tog, k4, *yo, k2tog tbl, k1, k2tog, yo, k3, yo, k2tog tbl, k1, k2tog, yo, k5, repeat from * to last 19 sts, yo, k2tog tbl, k1, k2tog, yo, k3, yo, k2tog tbl, k1, k2tog, yo, k4, k2tog tbl (multiple of 18 sts, plus 23).
• Row 9: K2tog, k4, *yo, k2tog tbl, k2, yo, k3tog tbl, [yo, k2, k2tog] twice, yo, k3, repeat from * to last 17 sts, yo, k2tog tbl, k2, yo, k3tog tbl, yo, k2, k2tog, yo, k4, k2tog tbl (multiple of 18 sts, plus 21).
• Row 11: K2tog, k4, *yo, k2tog tbl, k1, [k2tog, yo, k2] twice, k2tog, yo, k1, yo, k2tog tbl, k2, repeat from * to last 15 sts, yo, k2tog tbl, k1, k2tog, yo, k2, k2tog, yo, k4, k2tog tbl (multiple of 18 sts, plus 19).
• Row 13: K2tog, k4, *yo, k2tog tbl, k3, k2tog, yo, k2, k2tog, yo, k3, yo, k2tog tbl, k2, repeat from * to last 13 sts, yo, k2tog tbl, k3, k2tog, yo, k4, k2tog tbl (multiple of 18 sts, plus 17).
• Row 15: K2tog, k4, *yo, k2tog tbl, k1, k2tog, yo, k2, k2tog, yo, k1, k2tog, yo, k2, yo, k2tog tbl, k2, repeat from * to last 11 sts, yo, k2tog tbl, k1, k2tog, yo, k4, k2tog tbl (multiple of 18 sts, plus 15).
• Row 17: K2tog, k4, *yo, k3tog tbl, yo, k2, k2tog, yo, k2, yo, k3tog tbl, yo, k2, yo, k2tog tbl, k2, repeat from * to last 9 sts, yo, k3tog tbl, yo, k4, k2tog tbl (multiple of 18 sts, plus 13).
• Row 19: K2tog, k4, yo, k2tog tbl, k6, *k2tog, yo, k8, yo, k2tog tbl, k6, repeat from * to last 17 sts, k2tog, yo, k7, k2tog, yo, k4, k2tog tbl (multiple of 18 sts, plus 29).
• Row 21: K2tog, k4, yo, k2tog tbl, *k13, k2tog, yo, k1, yo, k2tog tbl, repeat from * to last 21 sts, k13, k2tog, yo, k4, k2tog tbl (multiple of 18 sts, plus 27).
• Row 23: K2tog, k4, yo, k2tog tbl, k4, *k2tog, yo, k5, k2tog, yo, k3, yo, k2tog tbl, k4, repeat from * to last 15 sts, k2tog, yo, k5, k2tog, yo, k4, k2tog tbl (multiple of 18 sts, plus 25).
• Row 25: K2tog, k4, yo, k2tog tbl, k3, *k2tog, yo, k4, k2tog, yo, k5, yo, k2tog tbl, k3, repeat from * to last 14 sts, [k2tog, yo, k4] twice, k2tog tbl (multiple of 18 sts, plus 23).
• Row 27: K2tog, k4, yo, k2tog tbl, k2, *k2tog, yo, k3, k2tog, yo, k2, k2tog, yo, k3, yo, k2tog tbl, k2, repeat from * to last 13 sts, k2tog, yo, k3, k2tog, yo, k4, k2tog tbl (multiple of 18 sts, plus 21).
• Row 29: K2tog, k7, *k2tog, yo, k5, yo, k2tog tbl, k3, k2tog, yo, k4, repeat from * to last 12 sts, k2tog, yo, k8, k2tog tbl (multiple of 18 sts, plus 19).
• Row 31: K2tog, k6, *k2tog, yo, k6, yo, k2tog tbl, k1, k2tog, yo, k5, repeat from * to last 11 sts, k2tog, yo, k7, k2tog tbl (multiple of 18 sts, plus 17).
• Row 33: K2tog, k4, *k2tog, yo, k1, yo, k2tog tbl, k5, yo, k3tog tbl, yo, k5, repeat from * to last 11 sts, k2tog, yo, k1, yo, k2tog tbl, k4, k2tog tbl (multiple of 18 sts, plus 15).
• Row 35: K2tog, k2, k2tog, yo, *k3, yo, k2tog tbl, k4, k2tog, yo, k5, k2tog, yo, repeat from * to last 9 sts, k3, yo, k2tog tbl, k2, k2tog tbl (multiple of 18 sts, plus 13).
• Row 37: K2tog, *k2tog, yo, k5, yo, k2tog tbl, k9, repeat from * to last 11 sts, k2tog, yo, k5, yo, [k2tog tbl] twice (multiple of 18 sts, plus 11).
• Row 39: K2tog, k1, *yo, k2tog tbl, k1, k2tog, yo, k13, repeat from * to last 8 sts, yo, k2tog tbl, k1, k2tog, yo, k1, k2tog tbl (multiple of 18 sts, plus 9).