Suppose you have this simplified input and you want to expand columns sequentially n
times:
A = [1 4
2 5
3 6];
szA = size(A);
n = 3;
There are few ways to do that:

Replicate, then reshape:
reshape(repmat(A,n,1),szA(1),n*szA(2))

Kronecker product:
kron(A,ones(1,n))

Using FEX:
expand()
:expand(A,[1 n])

Since R2015a,
repelem()
:repelem(A,1,n)
All yield the same result:
ans =
1 1 1 4 4 4
2 2 2 5 5 5
3 3 3 6 6 6