Problems Indexing an Array

Hi, I'm trying to index an array s, but I keep getting the error that the subscript indices must be real positive integers or logicals. Does anyone know how to fix this? Also for reference I am using version 2017b.

for t=1,2*n

    s(t)=symsum((W(j))*(X(j))^t, j ,1,m )
    t=t+1;
end

Answer 1

[Mischa Kim]

Without seeing the entire code, the only potential issue that I can see is that t must be integers starting at t = 1.