Zig Zag Rib Twist Pattern

Pattern
Cast on a multiple of 3 sts, plus 1.
Row 1 (RS): P1, *knit into back loop of second stitch (leaving stitch on left needle), knit into front of first stitch, then drop them both from the needle at the same time, P1; rep from * to end .
Row 2 (WS): K1, *Purl into second stitch (leaving stitch on left needle), purl into first stitch, then drop them both from the needle at the same time, K1, rep from * to end.
Rep Rows 1 - 2.