Cast on a multiple of 10 sts, + 2 and 18-row repeat.
Row 1: RS: K1, * yo, k8, k2tog; rep from * to last st, k1.
Row 2: P1, * p2tog, p7, yo, p1; rep from * to last st, p1.
Row 3: K1, * k2, yo, k6, k2tog; rep from * to last st, k1.
Row 4: P1, * p2tog, p5, yo, p3; rep from * to last st, p1.
Row 5: K1, * k4, yo, k4, k2tog; rep from * to last st, k1.

Row 6: P1, * p2tog, p3, yo, p5; rep from * to last st, p1.
Row 7: K1, * k6, yo, k2, k2tog; rep from * to last st, k1.
Row 8: P1, * p2tog, p1, yo, p7; rep from * to last st, p1.
Row 9: K1, * k8, yo, k2tog; rep from * to last st, k1.
Row 10: P1, * yo, p8, ssp; rep from * to last st, p1.
Row 11: K1, * ssk, k7, yo, k1; rep from * to last st, k1.
Row 12: P1, * p2, yo, p6, ssp; rep from * to last st, p1.
Row 13: K1, * ssk, k5, yo, k3; rep from * to last st, k1.
Row 14: P1, * p4, yo, p4, ssp; rep from * to last st, p1.
Row 15: K1, * ssk, k3, yo, k5; rep from * to last st, k1.
Row 16: P1, * p6, yo, p2, ssp; rep from * to last st, p1.
Row 17: K1, * ssk, k1, yo, k7; rep from * to last st, k1.
Row 18: P1, * p8, yo, ssp; rep from * to last st, p1.

Knitting abbreviations:
K: Knit | P: Purl | Yo: Yarn over.
K2tog: Knit 2 sts together | Ssk: Slip slip knit.
Purl: Purl 2 sts together | Ssp: Slip 2 stitches as if to knit, then slip the two slipped stitches back to the left needle, purl them together through the back loops.