Question:Multiply each term from a polynom by a coefficient

Question:Multiply each term from a polynom by a coefficient

Maple

Hi there,

I have a big polynomial expression involving powers of x and y, that comes from expanding a function in powers of x and y in polynomial form (I use series(convert(series(a,x=0,10),polynom),y=0,10) ). I want to multiply each of the terms by the factorial of the power of x and y it has. How can I do this?
I tried using Physics[Coefficient](a,x) but I get the error: it cannot compute the degree of the expression.
I tried using a double for with a double coeff to get each of the coefficients and the maybe be able to multiply them but I get the error "unable to compute coeff".

Is it because as expanding the series I have the term +O(y^11) that it cannot compute it?

I managed to substitute the x terms using subs(x^3=3!*x^3,x^5=5!*x^5,a). Obviously this is not very efficient since I need to write the substitution for each term, and since the ploynom is grouped in powers of y, this does not work for y (neither does algusbs).

[Edit 2]:

an example of it would be:

with result

And I want the coefficients for each x and y power to be multiplied by the factorial of those powers.

Thank you!

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