y=[y(1),y(2),...,y(n)]

x=[x(1),x(2),...,x(n)]

a=[a0,a1,...,am]=[a(1),a(2),...,a(m+1)]

y(p) = a0*x(p)^0 + a1*x(p)^1 + a2*x(p)^2 + ... + am*x(p)^m

y(1) = a(1)*x(p)^0 + a(2)*x(p)^1 + a(3)*x(p)^2 + ... + a(m+1)*x(p)^m.

y(p) = **sum** (from q=0 to m) **[a(q+1)*x(p)^q]**

syms q a x
f=a(q+1)*x(2)^q
y(2) = symsum(f, q, 0, m)

% Inputs , for example x=[1,2,3,..,10] and a=[5,6,7,8]

x=1:10
a=[5,6,7,8]

% m <= length(a)

m=3

% temporary matrices

[tx,ta] = meshgrid(x,a)
[~,tm]=meshgrid(x,0:m)
t=ta(1:m+1,:).*tx(1:m+1,:).^tm(1:m+1,:)

% y is your result and has equal elemnts to x matrix

y=sum(t,1)

% some outputs

y(2)
y(3)