Shown with a cast-on count of 18 stitches.  

• Rows 1 and 5 (RS): K18.
• Rows 2 and 6: P18.
• Row 3: [Yo, k1] 3 times, [k2tog] 6 times, [yo, k1] 3 times.
• Row 4: K18.
• Row 7: [Yo, k1] 3 times, [k2tog] twice, k4, [k2tog] twice, [yo, k1] 3 times (20 sts).
• Row 8: K20.
• Row 9: K9, yo, k2, yo, k9 (22 sts).
• Row 10: P22.
• Row 11: [Yo, k1] 3 times, [k2tog] 3 times, k1, yo, k2, yo, k1, [k2tog] 3 times, [yo, k1] 3 times (24 sts).
• Row 12: K24.
• Row 13: K10, yo, k4, yo, k10 (26 sts).
• Row 14: P26.
• Row 15: [Yo, k1] 3 times, [k2tog] 4 times, [yo, k1] twice, [k1, yo] twice, [k2tog] 4 times, [yo, k1] 3 times (28 sts).
• Row 16: K28.
• Row 17: K12, yo, k4, yo, k12 (30 sts).
• Row 18: P30.
• Row 19: [Yo, k1] 3 times, [k2tog] 4 times, k2, [yo, k1] twice, [k1, yo] twice, k2, [k2tog] 4 times, [yo, k1] 3 times (32 sts).
• Row 20: K32.
• Row 21: K14, yo, k4, yo, k14 (34 sts).
• Row 22: P34.
• Row 23: [Yo, k1] 3 times, [k2tog] 5 times, [k1, yo] 3 times, k2, [yo, k1] 3 times, [k2tog] 5 times, [yo, k1] 3 times (36 sts).
• Rows 24 and 28: K36.
• Rows 25 and 29: K36.
• Rows 26 and 30: P36.
• Rows 27 and 31: *[Yo, k1] 3 times, [k2tog] 6 times, [yo, k1] 3 times, repeat from *.