Shown with a cast-on count of 21 stitches.  

• Row 1 (RS): K4, p1, *yo, ssk, k1, p1, k1, p1, repeat from * to last 4 sts, k4.
• Row 2: K4, *k1, p1, k1, p3, repeat from * to last 5 sts, k5.
• Row 3: K4, p1, *yo, p1, ssk, p1, k1, p1, repeat from * to last 4 sts, k4.
• Rows 4, 6, 8, 12, and 16: K4, *k1, p1, k1, p1, k1, p1, repeat from * to last 5 sts, k5.
• Row 5: K4, p1, *yo, k1, p1, ssk, k1, p1, repeat from * to last 4 sts, k4.
• Row 7: K4, p1, *yo, p1, k1, p1, ssk, p1, repeat from * to last 4 sts, k4.
• Row 9: K4, p1, *k1, p1, k1, k2tog, yo, p1, repeat from * to last 4 sts, k4.
• Row 10: K4, *k1, p3, k1, p1, repeat from * to last 5 sts, k5.
• Row 11: K4, p1, *k1, p1, k2tog, p1, yo, p1, repeat from * to last 4 sts, k4.
• Row 13: K4, p1, *k1, k2tog, p1, k1, yo, p1, repeat from * to last 4 sts, k4.
• Row 14: K4, *k1, p2, k1, p2, repeat from * to last 5 sts, k5.
• Row 15: K4, p1, *k2tog, p1, k1, p1, yo, p1, repeat from * to last 4 sts, k4.