Query on SAP HANA Sizing Recommendation

Hi Experts,

Hope you all are doing well and safe.

I am new to HANA Technology and needs to clear some doubt. While studying the SAP HANA Implementation guide I came through the sizing recommendation section and have some doubts to clear. I am attaching the images which some of you will be familiar with.

Can anyone kindly explain the above calculation ?

According to this above diagram, what is the meaning of 3+1, what is the meaning of 1 here.

And why from 5+1 on wards the size got multiplied by 2 ?

From the Sizing Perspective these areas seem to be somewhat confusing.

Any suggestions is appreciated.

Thanks and Regards
Anurag Das
SAP Netweaver UK