Problem with multiplication n*(n+1)

I want to change the index of this 3 summations using only one index, so I need to calculate j = 2*(n*(n+1)+m-1)+s for using the new index j.

Why does n*(n+1) generate an error?

[madhan ravi]

show the full code

[John D'Errico]

Is n a vector? Do you know what the operator .* does, and why you need to use it INSTEAD of the * operator here? If not, then read the help for times.

help times

[Laura Passalacqua]

n isn't a vector

[Image Analyst]

You're not making it easy for us to help you, are you? Do you maybe have a picture of the formula with three sums that you can post (but only after reading this link)?

[Steven Lord]

What is the full and exact text of the error message you received? Show all the text displayed in red (and/or orange, if you also received warnings) in the Command Window when you run the code that performs the multiplication that throws the error.