How to set Reallyl Basic iterative sum

I want to sum up all n*sin(n*x)-terms. I've found that

f = n*sin(n*x)
for n = 1:10
    f(n+1) = n*sin(n*x);
end
sum(f)

works. However, in my view it's not that elegant. In other words, how to implement without using 'sum'?

Answer 1

[KSSV]

% f = n*sin(n*x) ; 
thesum = 0 ; 
for n = 1:10
    thesum = thesum+n*sin(n*x);
end