To reference an element of a list (the TI graphing calculator equivalent of a one-dimensional array) by index, use the format listName[Index]. A variable name followed by parentheses, rather than brackets, is interpreted as a function or program being passed whatever is in the parentheses as arguments.
Additionally, the equal sign is not an assignment operator. There are three ways to set a variable, where Var is the variable name and Expr is the expression to be evaluated and stored:
1. Var := Expr
2. Expr =: Var
3. Same as 2, but replace =: with the symbol you get by pressing ctrl+var on the keypad.
So your loop, rewritten with correct syntax, becomes:
For i, 1, 10
n[i] := randInt(1, 100)