One way:
x = [1 2 3 1 2 3 4 5 1 2 3 4 5 6 7 1 2 3 4 5 6 7 8 9];
But I'm guessing that's not what you meant.
Another way:
x = [];
for k = 3:2:9
x = [x, 1:k]
end
In general, it is not a good idea to "grow" a vector like this, by simply appending. It's better to define the vector length ahead of time, preallocating the memory. But, I'm feeling lazy right now.
