Here it is! I’ve actually done a few rounds past the waste yarn for the thumb hole (so I’ve done more than is shown).

The current version of the pattern is as follows:

Cast on 42 stitches (I used a cable cast-on)
R1: (k1, p2, k2, p2, k1, p2)* repeat til end
R2: same
R3: same except instead of k2 : k2tog, leave on left needle, knit into first of the k2tog stitches, slip both to right needle.

Repeat above til you’ve done round 3 four times.
On the next round m1 purled inbetween the 2 pattern stitches (k1p1k1).

Continue in new pattern for 13 rounds.

At start of the next round, knit 7 w/ waste yarn, move back to left needle, and continue in the original pattern.

For the next round, decrease that added purl stitch by slipping the first knit stitch, knitting the purl stitch, then PSSO.

Continue in pattern as long as desired.