Help with pattern

I’m knitting a baby vest and have hit a snag with these directions. Please help.
Shape Armholes
Bind off 3 sts at beginning of next 0 (2,
2, 4) rows, then 2 sts at beginning of
next 4 (2, 2, 0) rows – 37 (39, 41, 43) sts.
I’m knitting the largest size and I’m unsure of what to do after binding off 3 sts at the beginning of the next four rows. I did that and have 51 sts left. How do I get to 43?

Thanks for any help you may provide.

Welcome!
You started with 63sts, bound off 3sts x4 and you’re supposed to have 43? Hmmm.
Can you give us the name of the pattern?