Find the first, fourth, and eighth terms of the sequence. A (n) = - 2 ∙ 2x - 1

Just substitute the term number for the variable and solve

A (1) = - 2 * 2 (1) - 1 = - 2 * 2 - 1 = - 4 - 1 = - 5

A (4) = - 2 * 2 (4) - 1 = - 2 * 8 - 1 = - 16 - 1 = - 17

A (8) = - 2 * 2 (8) - 1 = - 2 * 16 - 1 = - 32 - 1 = - 33