How to increase a symbol in a row matrix?

I am trying to make a function in which by putting the value of n, the number of symbols in that row matrix comes to be n.

For example, Suppose I assign a function coeff(n) = [a1 a2 a3 a4 a5 ... an].

Now if i enter n = 3, coeff(3) = [a1 a2 a3].

I tried starting this way.

function[A] = coeff(n)

Henceforth i tried multiple codes but i failed. Please help. Thank you in advance.

Answer 1

[KSSV]

n = 4 ;
syms a [1 n] ;
a

a =