Let an be the nth term of the series 5 + 8 + 14 + 23 + 35 + 50 +.... and Sn = ⁿ∑ₖ₌₁ a k. Then S₃₀ - a₄₀ is equal to
(1) 11260
(2) 11280
(3) 11290
(4) 11310