The sum of all possible values of \( n \in \mathbb{N} \), so that the coefficients of \( x \), \( x^{2} \) and \( x^{3} \) in the expansion of \( (1 + x^{2})(1 + x)^{n} \), are in arithmetic progression is:
\( 12 \)
\( 7 \)
\( 9 \)
\( 3 \)