Answer:
Explanation:
a(n) = n² - 3n - a(n-1) and a(1) = 4
We have a(1) = 4 and want a(2) (for which n = 2).
a(2) = 2² - 3(2) - a(2-1) → a(2) = 4 - 6 - 4 = -6 = a(2)
a(3) = 3² - 3(3) - (-6) = 9 - 9 + 6 = 6 = a(3)
a(4) = 4² - 3(4) - 6 = 16 - 12 - 6 = -2 = a(4)
a(5) = 5² - 3(5) + 2 = 12 = a(5)