The first picture has six white tiles, the second picture has 10, and the third picture has 14.

As can be seen from the observation chart, every time a black tile is added, four white tiles are added (except the first picture).

So set y white tiles and x black tiles.

According to the above analysis, we can get the equivalence relation: y=6+4(n- 1).

Y=4n+2。

So the nth group has (4n+2) white tiles.

Don't forget the brackets in the spaces.