Shown with a cast-on count of 2 stitches.  

• Round 1: [K1, yo] twice (4 sts).
• Rounds 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, and 36: Knit.
• Round 3: [K1, yo] 4 times (8 sts).
• Round 5: K1, yo, k2tog, [k1, yo] twice, k1, ssk, yo (10 sts).
• Round 7: K1, yo, k2tog, k2, yo, k1, yo, k2, ssk, yo (12 sts).
• Round 9: K1, yo, k2tog, k3, yo, k1, yo, k3, ssk, yo (14 sts).
• Round 11: K1, yo, k2tog, k4, yo, k1, yo, k4, ssk, yo (16 sts).
• Round 13: K1, yo, k2tog, ssk, k2, yo, [k1, yo] 3 times, k2, k2tog, ssk, yo (18 sts).
• Round 15: K1, yo, k2tog, ssk, [k2, yo] twice, k1, [yo, k2] twice, k2tog, ssk, yo (20 sts).
• Round 17: K1, yo, k2tog, yo, ssk, k2, yo, k3, yo, k1, yo, k3, yo, k2, k2tog, yo, ssk, yo (24 sts).
• Round 19: [K1, yo] 4 times, ssk, k2, yo, ssk, k5, k2tog, yo, k2, k2tog, yo, [k1, yo] 3 times (30 sts).
• Round 21: K1, yo, k2tog, k1, [yo, k1] twice, ssk, yo, ssk, k2, yo, ssk, k3, k2tog, yo, k2, k2tog, yo, k2tog, k1, [yo, k1] twice, ssk, yo (32 sts).
• Round 23: K1, yo, k2tog, k2, yo, k1, yo, k2, ssk, yo, ssk, k2, yo, ssk, k1, k2tog, yo, k2, k2tog, yo, k2tog, k2, yo, k1, yo, k2, ssk, yo (34 sts).
• Round 25: K1, yo, k2tog, k3, yo, k1, yo, k3, ssk, yo, ssk, k2, yo, sl1-k2tog-psso, yo, k2, k2tog, yo, k2tog, k3, yo, k1, yo, k3, ssk, yo (36 sts).
• Round 27: K1, yo, k2tog, k4, yo, k1, yo, k4, ssk, yo, ssk, k5, k2tog, yo, k2tog, k4, yo, k1, yo, k4, ssk, yo (38 sts).
• Round 29: K1, yo, k2tog, ssk, k2, yo, [k1, yo] 3 times, k2, k2tog, ssk, yo, ssk, k3, k2tog, yo, k2tog, ssk, k2, yo, [k1, yo] 3 times, k2, k2tog, ssk, yo (40 sts).
• Round 31: K1, yo, k2tog, ssk, [k2, yo] twice, k1, [yo, k2] twice, k2tog, ssk, yo, ssk, k1, k2tog, yo, k2tog, ssk, [k2, yo] twice, k1, [yo, k2] twice, k2tog, ssk, yo (42 sts).
• Round 33: K1, yo, k2tog, yo, ssk, k2, yo, k3, yo, k1, yo, k3, yo, k2, k2tog, ssk, yo, sl1-k2tog-psso, yo, k2tog, ssk, k2, yo, k3, yo, k1, yo, k3, yo, k2, k2tog, yo, ssk, yo (46 sts).
• Round 35: [K1, yo] 4 times, ssk, k2, yo, ssk, k5, k2tog, yo, k2, sl1-k2tog-psso, [yo, k1] 3 times, yo, k3tog, k2, yo, ssk, k5, k2tog, yo, k2, k2tog, [yo, k1] 3 times, yo (52 sts).
• Round 37: K1, yo, k2tog, k1, [yo, k1] twice, ssk, yo, ssk, k2, yo, ssk, k3, k2tog, yo, k2, k2tog, yo, k2tog, k1, [yo, k1] twice, ssk, yo, ssk, k2, yo, ssk, k3, k2tog, yo, k2, k2tog, yo, k2tog, k1, [yo, k1] twice, ssk, yo (54 sts).