Shown with a cast-on count of 18 stitches.  

• Row 1 (RS): K4, yo, k5, yo, k5, yo, k4 (21 sts).
• Row 2 (RS): P3, k3, sl1-k2-psso, k3, sl1-k2-psso, k3, p3 (19 sts).
• Row 3 (RS): K2, ssk, k3, yo, k5, yo, k3, k2tog, k2.
• Row 4 (RS): P3, k5, sl1-k2-psso, k5, p3 (18 sts).
• Row 5 (RS): K2, ssk, k5, yo, k5, k2tog, k2 (17 sts).
• Row 6 (RS): P3, k1, sl1-k2-psso, k3, sl1-k2-psso, k1, p3 (15 sts).
• Row 7 (RS): K2, ssk, k1, yo, k5, yo, k1, k2tog, k2.
• Row 8 (RS): P3, k3, sl1-k2-psso, k3, p3 (14 sts).
• Row 9 (RS): K2, ssk, k3, yo, k3, k2tog, k2 (13 sts).
• Row 10 (RS): P3, k7, p3.
• Row 11 (RS): K2, ssk, k5, k2tog, k2 (11 sts).
• Row 12 (RS): P3, k1, sl1-k2-psso, k1, p3 (10 sts).
• Row 13 (RS): K2, ssk, k1, yo, k1, k2tog, k2 (9 sts).