Help with Debbie Bliss bear faced pyjama case

Pattern Central
1

Hi

Can anyone help?

The pattern starts with casting on 15 sts and then the following…

Moss st row: K1,[p1,k1] to end. This row sets the moss st.

Next row: Kpk, [p1,k1] to last 2 sts, p1, kpk.

Rep the last row 3 times more. 31 sts.
Inc and take into moss st one st st at each end of next 11 rows. 53 sts.

I can see how you get from 31 to 53 but not from 15 to 31 - can anyone help??

Thanks

2

"Next row: Kpk, [p1,k1] to last 2 sts, p1, kpk.

Rep the last row 3 times more. 31 sts."
The kpk is all into a single stitch so it’s an increase of 2 sts at each end of the row, or 4sts total per increase row. Do it once and repeat 3 times more for and increase of 16sts (from 15 to 31sts).