Shown with a cast-on count of 5 stitches.  

• Rounds 1, 5, 9, 13, 17, 21, 25, 29, 33, and 37: Knit.
• Round 2: P2, (p1, k1, p1) in next st, p2 (7 sts).
• Round 3: K3, (k1, yo, k1) in next st, k3 (9 sts).
• Rounds 4, 8, 12, 16, 18, 20, 24, 28, 30, 32, 36, and 40: Purl.
• Round 6: P4, (p1, k1, p1) in next st, p4 (11 sts).
• Round 7: Ssk, k3, yo, (k1, yo, k1) in next st, yo, k3, k2tog (13 sts).
• Round 10: P6, (p1, k1, p1) in next st, p6 (15 sts).
• Round 11: Ssk, ssk, k1, [k1, yo] twice, (k1, yo, k1) in next st, [yo, k1] twice, k1, k2tog, k2tog (17 sts).
• Round 14: P8, (p1, k1, p1) in next st, p8 (19 sts).
• Round 15: [Ssk] 3 times, [k1, yo] 3 times, (k1, yo, k1) in next st, [yo, k1] 3 times, [k2tog] 3 times (21 sts).
• Round 19: [Ssk] 3 times, [k1, yo] 4 times, (k1, yo, k1) in next st, [yo, k1] 4 times, [k2tog] 3 times (25 sts).
• Round 22: P10, ssp, p1, p2tog, p10 (23 sts).
• Round 23: [Ssk] 3 times, [k1, yo] 5 times, (k1, yo, k1) in next st, [yo, k1] 5 times, [k2tog] 3 times (29 sts).
• Round 26: P12, ssp, p1, p2tog, p12 (27 sts).
• Round 27: [Ssk] 3 times, [k1, yo] 6 times, k3, [yo, k1] 6 times, [k2tog] 3 times (33 sts).
• Round 31: [Ssk] 3 times, [k1, yo] 6 times, k1, k2tog, k3, ssk, k1, [yo, k1] 6 times, [k2tog] 3 times (37 sts).
• Round 34: P18, (p1, k1, p1) in next st, p18 (39 sts).
• Round 35: [Ssk] 3 times, [k1, yo] 6 times, k1, k2tog, k2tog, k5, ssk, ssk, k1, [yo, k1] 6 times, [k2tog] 3 times (41 sts).
• Round 38: P20, (p1, k1, p1) in next st, p20 (43 sts).
• Round 39: [Ssk] 3 times, [k1, yo] 6 times, k1, k2tog, k2tog, k9, ssk, ssk, k1, [yo, k1] 6 times, [k2tog] 3 times (45 sts).