Answer:
Explanation:
a₁ = -3 = (-1)¹×3
a₂ = 6 = (-1)²×2×3
a₃ = -28 = (-1)³×2²×7
a₄ = 72 = (-1)⁴×2³×3²
a₅ = -360 = (-1)⁵×2³×3²×5
a₆ = 2160 = (-1)⁶×2⁴×3³×5
That's as far as I got. I can predict that a₇ is a multiple of -32 and a₈ is a multiple of 64, but I don't see the pattern with the other factors.