mods:
using kfb instead of yo for the center increase
I like the way it looks better than the center spine
on purl rows I am knitting the first and last stitch

So I started CO 3 stitches
row 1: kfb,kfb,k1
row 2: purl
row 3: k1, yo, kfb,kfb,k1,yo,k1

remember to mark the RS with pin