Cast on an even number of stitches
Row 1: Knit (You will only work Row 1 once, it is not included in the repeat)
Row 2: Knit 1 *K2tog* Knit last stitch
Row 3: *Knit 1, Make one by knitting into the bar between the stitch you just knit and the next stitch on your left needle* Knit two. (When you come to the last two stitches, you will not knit the bar between them. If you do, this will give you an unnecessary extra stitch)
Row 4: Knit
Row 5: Purl
Repeat from Row 2 for pattern.