Shown with a cast-on count of 51 stitches.  

• Rows 0 and 4 (RS): K1, [k3tog, [k1, brSl] 4 times, k1, k3tog, k1] 3 times, brSl, k1 (39 sts).
• Rows 1 and 5: BrSl, k1, brSl, k1, brSl, [ctr dbl inc, brSl, ctr dbl inc, brSl, k1, brSl, k1, brSl, k1, brSl, k1, brSl] twice, ctr dbl inc, brSl, ctr dbl inc, brSl, k1, brSl, k1, brSl, k1, brSl (51 sts).
• Rows 2 and 6: K1, brSl, k1, [k3tog, [k1, brSl] 4 times, k1, k3tog, k1] twice, k3tog, [k1, brSl] 4 times, k1, k3tog, k1 (39 sts).
• Rows 3 and 7: BrSl, k1, brSl, k1, brSl, k1, brSl, [ctr dbl inc, brSl, ctr dbl inc, brSl, k1, brSl, k1, brSl, k1, brSl, k1, brSl] twice, ctr dbl inc, brSl, ctr dbl inc, brSl, k1, brSl, k1, brSl (51 sts).