Shown with a cast-on count of 22 stitches.  

• Rows 1-3 and 14 (RS): Purl.
• Row 4 (RS): *P3, k1, p3, k1, p3, repeat from *.
• Row 5 (RS): *P3, kfb, p3, kfb, p3, repeat from * (multiple of 13 sts).
• Row 6 (RS): *P3, k1 tbl, kfb, p3, kfb, k1 tbl, p3, repeat from * (multiple of 15 sts).
• Row 7 (RS): *P3, k1 tbl, k1, kfb, p3, kfb, k1, k1 tbl, p3, repeat from * (multiple of 17 sts).
• Row 8 (RS): *P3, k1 tbl, k2, ctr dbl inc, p3, ctr dbl inc, k2, k1 tbl, p3, repeat from * (multiple of 21 sts).
• Row 9 (RS): *P3, k1 tbl, k4, ctr dbl inc, p3, ctr dbl inc, k4, k1 tbl, p3, repeat from * (multiple of 25 sts).
• Row 10 (RS): *P3, k1 tbl, k4, k3tog, p3, sl1-k2tog-psso, k4, k1 tbl, p3, repeat from * (multiple of 21 sts).
• Row 11 (RS): *P3, k1 tbl, k2, k3tog, p3, sl1-k2tog-psso, k2, k1 tbl, p3, repeat from * (multiple of 17 sts).
• Row 12 (RS): *P3, k1 tbl, k3tog, p3, sl1-k2tog-psso, k1 tbl, p3, repeat from * (multiple of 13 sts).
• Row 13 (RS): *P3, k2tog, p3, ssk, p3, repeat from * (multiple of 11 sts).
• Row 15 (RS): *P5, 1-to-5 inc, p5, repeat from * (multiple of 15 sts).
• Row 16 (RS): *P5, k2, ctr dbl inc, k2, p5, repeat from * (multiple of 17 sts).
• Row 18 (RS): *P5, k3, ctr dbl inc, k3, p5, repeat from * (multiple of 19 sts).
• Row 19 (RS): *P5, k9, p5, repeat from *.
• Row 20 (RS): *P5, k9tog, p5, repeat from * (multiple of 11 sts).