Help with a pattern

I am doing the Sassy Seed Stitch sweater from the Spring 2013 issue of Creative Knitting. Actually for the second time. I am working on the right front and I can’t remember how id did it.

With 31 stitches on my needle:

Dec 1 st at armhole edge [every 4th row] 2 times, then [every 3rd row] 16 times. At the same time when armhole measures 4.5" bind off 3 sts at neck edge. Continuing raglun dec, dec 1 st at neck edge [every row] 8 times, then work even at neck edge- 2 sts rem.

I’m trying to count backwardsfrom the last row,2 stitches, to determine when to start the neck side decrease. why am i having a brain block? Help?

I hate those brain freezes!
Can you measure the length of the armhole and when you get to 4.5", start the bind off at the neck edge? If you bound off a few sts to start the armhole, measure straight up from there (not on a slanted line along the raglan edge). If the armhole starts with the raglan dec, measure from that first decrease, straight up until you have 4.5".
Since it’s the right front, you’ll be binding off at the beginning of a right side row.

It’s a very sweet pattern.