\[a_{1} = - 4;\ \ a_{2} = 3;\ \ \]
\[a_{n + 2} = a_{n} + {2a}_{n + 1}\]
\[a_{3} = a_{1} + 2a_{2} = - 4 + 6 = 2;\]
\[a_{4} = a_{2} + 2a_{3} = 3 + 4 = 7.\]