Shown with a cast-on count of 90 stitches.  

• Round 1: K90.
• Rounds 2, 5-6, 9-10, and 13-14: Knit.
• Rounds 3, 7, 11, 15, and 17: Purl.
• Round 4: *[Yo, k1] 3 times, yo, [k2tog] 3 times, [ssk] 3 times, [yo, k1] 3 times, repeat from * (95 sts).
• Round 8: *[Yo, k1] 3 times, yo, [k2tog] 3 times, [ssk] 3 times, [yo, k1] 4 times, repeat from * (105 sts).
• Round 12: *[Yo, k1] 3 times, yo, k1, [k2tog] 3 times, [ssk] 3 times, k1, [yo, k1] 4 times, repeat from * (115 sts).
• Round 16: *[Yo, k1] 4 times, yo, k1, [k2tog] 3 times, [ssk] 3 times, k1, [yo, k1] 5 times, repeat from * (135 sts).