Shown with a cast-on count of 39 stitches.  

• Rows 1, 5, and 15 (RS): K1, p1, *k17, p1, repeat from * to last st, k1.
• Rows 2, 4, 16, and 18: P1, knit to last st, p1.
• Rows 3 and 17: K1, p1, *yo, k2tog, repeat from * to last st, k1.
• Rows 6 and 14: P1, *k1, p17, repeat from * to last 2 sts, k1, p1.
• Row 7: K1, p1, *k2tog, k6, yo, k1, yo, k6, ssk, p1, repeat from * to last st, k1.
• Rows 8 and 10: P1, *k1, ssp, p13, p2tog, repeat from * to last 2 sts, k1, p1 (multiple of 16 sts, plus 3).
• Row 9: K1, p1, *k2tog, k4, [yo, k1] 3 times, yo, k4, ssk, p1, repeat from * to last st, k1 (multiple of 18 sts, plus 3).
• Row 11: K1, p1, *k2tog, k2, [yo, k1] 7 times, yo, k2, ssk, p1, repeat from * to last st, k1 (multiple of 22 sts, plus 3).
• Row 12: P1, *k1, ssp, p17, p2tog, repeat from * to last 2 sts, k1, p1 (multiple of 20 sts, plus 3).
• Row 13: K1, p1, *k2tog, k15, ssk, p1, repeat from * to last st, k1 (multiple of 18 sts, plus 3).
• Repeat rows 5-18.