howmany published books does amir have when he goes to visit rahim? what childhood memory of amir and rahim have that rahim was forgotten? chapter 15

Rahim had given a notebook to Amir. It was one of the only things Amir brought with them when they fled to Pakistan, but Rahim had forgotten.

I'm not sure about the first part of your question and will need to look further.

Amir had published four books before going to see Rahim.