Shown with a cast-on count of 40 stitches.  

• Rows 1, 3, and 17 (RS): Knit.
• Rows 2, 4, 6, 8, 10, 12, 14, 16, and 18: Purl.
• Row 5: *K8, k2tog, yo, yo, ssk, k8, repeat from *.
• Row 7: *K3, [k2tog] twice, yo, k1, yo, k4, yo, k1, yo, [ssk] twice, k3, repeat from *.
• Row 9: *K2, k2tog, yo, k12, yo, ssk, k2, repeat from *.
• Row 11: *K1, k2tog, yo, k14, yo, ssk, k1, repeat from *.
• Row 13: *K7, k2tog, yo, k2, yo, ssk, k7, repeat from *.
• Row 15: *Yo, ssk, k2tog, k2tog, yo, k1, yo, k6, yo, k1, yo, ssk, ssk, k2tog, yo, repeat from *.
• Row 19: *K2tog, yo, k16, yo, ssk, repeat from *.