how to calculate this term

I need to calculate this term in the article they told me that

What is exactly the base

[Azzi Abdelmalek]

Can you explain?

[jenny jenny]

I need to calculate this term in matlab

this is the differentielle equation but I don't understand how to calculate this values (3 , 2 , 6 , 11, 6)

Answer 1

[Walter Roberson]

We do not know. If (X) subscript 3 had been x^3 + 3 * x^2 + 2 * x instead of x^3 + 3 * x^2 + 2 * z then there would have been a simple explanation, but that z by itself with no other z really throws things off.

If it had be x instead of z, then the formula would have been for the Pochhammer symbol for the "rising factorial"; see https://en.wikipedia.org/wiki/Pochhammer_symbol

[Roger Stafford]

This is almost certainly the Pochhammer symbol with the erroneous 'z' replaced by 'x' and the 'n' made a superscript rather than a subscript. The article referenced by Walter shows how it can be systematically computed in an iterative manner.

[jenny jenny]

thank you for your answer this is the pochhammer_symbol thnaks a lot :)