Shown with a cast-on count of 18 stitches.  

• Row 1 (RS): K9, yo, k1, yo, k4, k3tog, k1.
• Rows 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, and 40: Purl.
• Rows 3, 15, and 27: K10, yo, k1, yo, k3, k3tog, k1.
• Rows 5, 17, and 29: K11, yo, k1, yo, k2, k3tog, k1.
• Rows 7, 19, and 31: K1, k3tog, k4, yo, k1, yo, k3, yo, k1, yo, k1, k3tog, k1.
• Rows 9, 21, and 33: K1, k3tog, k3, yo, k1, yo, k10.
• Rows 11, 23, and 35: K1, k3tog, k2, yo, k1, yo, k11.
• Rows 13 and 25: K1, k3tog, k1, yo, k1, yo, k3, yo, k1, yo, k4, k3tog, k1.
• Row 37: K1, k3tog, k1, yo, k1, yo, k12.
• Row 39: K18.