Matlab LPF Cascade Implementation

x = [1 zeros(1, N-1)];

Cascade...

B = [1 1];
A = [1];
y1 = filter(B, A, x);
y2 = filter(B, A, y1);
y3 = filter(B, A, y2);
y4 = filter(B, A, y3);

Or Simply...

B = [1 5 10 10 5 1];
A = [1];
y = filter(B, A, x);