Вопрос:

Ответ:

\[c_{1} = 4;\ \ c_{n + 1} = 2c_{n}\]

\[c_{2} = 2 \cdot 4 = 8;\]

\[c_{3} = 2 \cdot 8 = 16;\]

\[c_{4} = 2 \cdot 16 = 32;\]

\[c_{5} = 2 \cdot 32 = 64.\]