Sorting Permutation Matrix for Rows With Specific Consecutive Values

This code:

n = 3;
v = [1:n 1:n 1:n];
P = nchoosek(v,3);
A = unique(P,'rows');

Produces a Matrix of unique permutations of 1,2 & 3. eg.

1 1 1

1 2 1

1 2 2

1 3 3

etc

I want to sort the resulting rows, eliminating rows with any number of consecutive ones and twos, but NOT consecutive 3's. So in this example (composed of 4 of the 27 rows of A) rows 1 and 3 are no go's but 2 and 4 are fine. I experimented with 'diff(X,n,dim)' but couldn't find an elegant solution.

Thanks in advance.