How I can omit O() term in a series expansion so that the expansion remains a simpler polynomial only?

How can I get the correct multiset power set of a hashmset in Maple? For example for the following hasmset s I have two different answers in Maple and MuPad. I need to compute MuPad like answer in Maple:

>s := hashmset:-new( [ a, 4 ], [ c,3 ] );
                  s := table(sparse, [a = 4, c = 3])

> combinat:-powerset(entries(s));

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