Shown with a cast-on count of 13 stitches.  

• Row 1 (RS): K2, [yo, k1, yo, k1] 5 times, k1 (23 sts).
• Rows 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, and 40: Purl.
• Rows 3, 7, 11, 15, 19, 23, 27, 31, 35, and 39: Knit.
• Row 5: K2, [yo, k3, yo, k1] 5 times, k1 (33 sts).
• Row 9: K2, [yo, k5, yo, k1] 5 times, k1 (43 sts).
• Row 13: K2, [yo, k7, yo, k1] 5 times, k1 (53 sts).
• Row 17: K2, [yo, k9, yo, k1] 5 times, k1 (63 sts).
• Row 21: K2, [yo, k11, yo, k1] 5 times, k1 (73 sts).
• Row 25: K2, [yo, k13, yo, k1] 5 times, k1 (83 sts).
• Row 29: K2, [yo, k15, yo, k1] 5 times, k1 (93 sts).
• Row 33: K2, [yo, k17, yo, k1] 5 times, k1 (103 sts).
• Row 37: K2, [yo, k19, yo, k1] 5 times, k1 (113 sts).