<image>**Problem Description:** As shown in the figure, the following geometric shapes are composed of small cubes with an edge length of 1 arranged on the ground according to a certain pattern. The exposed surfaces are then painted (the bottom surface is not painted). The number of small cubes in the given geometric shape with only two faces painted is:



1st geometric shape: The number of cubes in the bottom layer = 4;

2nd geometric shape: The number of cubes in the bottom layer + middle layer + top layer = 4 + 4 + 4 = 12;

3rd geometric shape: The number of cubes in the bottom layer + two middle layers + top layer = 4 + 8 + 8 = 20;

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Summarize the pattern and answer the following questions:

(1) How many small cubes with only two faces painted are there in the 4th geometric shape?
(2) How many small cubes with only two faces painted are there in the \( n \)th geometric shape? (Express it using a formula containing the letter \( n \).)