Big Book of Knitting Stitch Patterns p.138
Work 3-to-3 gather this way instead: k3tog and leave on left needle, k first st again, knit remaining 2 sts together, and drop those 3 sts from left needle
Shown with a cast-on count of 6 stitches.
1 2 3 4 5 Horizontal repeats
1 2 3 4 5 Vertical repeats