Rolling average based on a dynamic sequence measure

Hi,

I am trying to calculate a dynamic 2-sequence rolling average based on the calulated table below.

First I created a dynamic sequence number that updates with slicers. The column is called "Løpenummer" in Norwegian, but it is a dynmic sequence number (starting on 1 and stops at 151 when slicer is applied in the example below).

Secondly I created a measure that accumulates turnover "Akkumulert omsetning".

But now I am trying to calculate a 2 sequence rolling average based on "Akkumulert omsetning". That is, the average for sequence number 1 and 2 is ((2 + 9,75)/2) equals 5,9. The average for sequence 2 and is ((9,75 + 28,75)/2) equals 19,8. And so on and so forth.

Hope someone is able to help me with this. Thanks a lot in advance 🙂