Shown with a cast-on count of 18 stitches.  

• Row 1 (RS): [K2, kfb, k3, kfb, k2] twice (22 sts).
• Row 2: [K11] twice.
• Row 3: [K2, kfb, k5, kfb, k2] twice (26 sts).
• Row 4: [K13] twice.
• Row 5: [K2, yo, k1, yo, k7, yo, k1, yo, k2] twice (34 sts).
• Row 6: [K17] twice.
• Row 7: [K2, yo, k1, yo, k11, yo, k1, yo, k2] twice (42 sts).
• Row 8: [K21] twice.
• Row 9: [K2, yo, k1, yo, k15, yo, k1, yo, k2] twice (50 sts).
• Row 10: [K25] twice.