Hi Franck,

I agree the table you show here is the correct output of the formula you calculated.
You can compare your table values with the orange spots (& orange line drawn) in my latest graph; this is it, we are on the same page.

But my concern is, this orange line (your table, so), does not hit any close enough the blue squares, apart from the 125 nodes spot (7 on the x-axis) and 500 nodes spot (9 on the x-axis). The orange line diverges a lot from the others and does not fit the trend.

I trust you calculated it correctly, but most probably you used other points as input for interpolation. The input sample I used is page 5 (results so far from games shared here):
Excel provided automatically the blue line (feature: add a trend line, choice linear) - It obviously fits better than the orange one.
So, to answer your question, the so-called "171,4" formula is the one Excel displays for the blue line.
Kind regards,
Eric