2/1/2 RPC = Cable Twist: Slip next 3 sts to cable needle and hold to back of work, k2, slip last st from cable needle to left needle, p1, k remaining 2 sts from cable needle.
Shown with a cast-on count of 27 stitches.
1 2 3 4 5 Horizontal repeats
1 2 3 4 5 Vertical repeats