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Mathcad Prime 12.0.0.0 sum wrong result
Hello,
Mathcad Prime 12.0.0.0 result:

Wolfram Mathematica result:

Hello,
Mathcad Prime 12.0.0.0 result:

Wolfram Mathematica result:

Note the lower index on the summation sign:

Could also have:

Clearly an error in the case of your original though, as the right-hand side can’t be a function of the summation index.
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