Shown with a cast-on count of 18 stitches.  

• Rows 1, 3, 5, 7, 9, 11, 13, 15, and 17 (RS): K2, yo, knit (1 more st).
• Rows 2, 4, 6, 8, 10, 12, 14, 16, and 18: P2, p2tog, p1, p2tog, purl to last 2 sts, p2 (2 fewer sts).
• Rows 19, 21, 23, 25, 27, 29, 31, 33, and 35 (RS): K2, yo, k1, yo, knit (2 more sts).
• Rows 22, 24, 26, 28, 30, 32, 34, and 36: P2, p2tog, purl to last 4 sts, yo, p1, yo, p1, p2 (1 more st).