Shown with a cast-on count of 34 stitches.  

• Rows 1 and 3 (RS): K34.
• Rows 2, 4, 6, 8, 10, 12, 16, and 18: Purl.
• Row 5: K1, *yo, k1, repeat from * (67 sts).
• Rows 7, 11, and 17: K1, *k1, yo, sl1-k2tog-psso, yo, k2, repeat from *.
• Rows 9 and 19: K1, *k1, yo, sl1-k2tog-psso PB, yo, k2, repeat from *.
• Rows 13 and 15: Knit.
• Row 14: P1, *yo, p1, repeat from * (133 sts).
• Row 21: K1, *k1, yo, sl1-k2tog-psso, yo, k2, repeat from *.