Shown with a cast-on count of 36 stitches.  

• Row 1 (RS): K1, *ssk, k13, k2tog, repeat from * to last st, k1 (multiple of 15 sts, plus 2).
• Rows 2, 4, 6, and 8: Purl.
• Row 3: K1, *ssk, k11, k2tog, repeat from * to last st, k1 (multiple of 13 sts, plus 2).
• Row 5: K1, *ssk, k9, k2tog, repeat from * to last st, k1 (multiple of 11 sts, plus 2).
• Row 7: K1, *ssk, yo, [k1, yo] 7 times, k2tog, repeat from * to last st, k1 (multiple of 17 sts, plus 2).