Code keeps entering values into array backwards

Code keeps entering values into array backwards

So I have this code, where I'm trying to figure out how many forground
layers will be in a map :
int layerNum=5 //in the current map it has 5 layers
int index = 3 //in the current map
fgLayers = new int[layerNum - (index + 1)];
for (int x = 0; x < fgLayers.length; x++) {
fgLayers[x] = layerNum - x - 1;
Gdx.app.log(ChromeGame.LOG, fgLayers[x] + "");
}
However, it puts the values into the fgLayers array backwards so instead
of 3,4 it would 4,3. I need it to be in the right order because each layer
has certain images on it, which look improper when placed in a different
order.
Unfortunately, I cannot see where I'm going wrond in this piece of code, I
tried switching where it starts of at in the for loop (starts at
fgLayers.length, ends at 0) but that didnt work either.