Techniques used 
K: Knit
P: Purl
Yo: Yarn over
K2tog: Knit 2 together
Ssk: Slip slip knit
  • Sskpo: Slip slip knit, then place the stitch back on the left-hand needle. Lift the second stitch on the left-hand needle over the ssk loop, then return the ssk loop to the right-hand needle.
Pattern
Multiple of 12,  + 9.
Row 1 (RS): k4, *k2tog, yo, k1, yo, ssk, k7*, k2tog, yo, k3.
Rows 2, 4, 6, 8, 10, 12, 14, 16, 18, 20: purl.
Row 3: k3, *k2tog, yo, k1, (yo, ssk) x2, k5*, k2tog, yo, k1, yo, ssk, k1.
Row 5: k2, *k2tog, yo, k1, (yo, ssk) x3, k3*, k2tog, yo, k1, yo, ssk, k2.
Row 7: k1, *k2tog, yo, k1, (yo, ssk) x4, k1*, k2tog, yo, k1, (yo, ssk) x2, k1.
Row 9: k2tog, yo, k1, *(yo, ssk) x4, yo, sskpo, yo, k1*, (yo, ssk) x2, k2.
Row 11: k1, yo, ssk, *k7, k2tog, yo, k1, yo, ssk*, k6.
Row 13: k2, yo, ssk, *k5, k2tog, yo, k1, (yo, ssk) x2*, k5.
Row 15: k1, yo, ssk, yo, ssk, *k3, k2tog, yo, k1, (yo, ssk) x3*,  k4.
Row 17: k2, yo, ssk, yo, ssk, *k1, k2tog, yo, k1, (yo, ssk) x4*, k3.
Row 19: k1, (yo, ssk) x2, *yo, sskpo, yo, k1, (yo, ssk) x4*, yo, ssk, k2.
Repeat rows 1-20.