Shown with a cast-on count of 22 stitches.  

• Rows 1, 3, 37, and 39 (RS): *Yo, k1, k2tog, yo, k2tog, yo, k4, k2tog, repeat from *.
• Rows 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, and 40: K1, yo, k2tog, purl.
• Rows 5, 7, 33, and 35: *Yo, k1, k2tog, yo, k1, k2tog, yo, k3, k2tog, repeat from *.
• Rows 9, 11, 29, and 31: *Yo, k1, k2tog, yo, k2, k2tog, yo, k2, k2tog, repeat from *.
• Rows 13, 15, 25, and 27: *Yo, k1, k2tog, yo, k3, k2tog, yo, k1, k2tog, repeat from *.
• Rows 17, 19, 21, and 23: *Yo, k1, k2tog, yo, k4, k2tog, yo, k2tog, repeat from *.