Guest Session: 1 Question Remaining. Create Account to save progress.
Login
Recursionhard
0:00.0

The Fibonacci sequence is defined by F1=1F_1 = 1F1​=1, F2=1F_2 = 1F2​=1, and Fn=Fn−1+Fn−2F_n = F_{n-1} + F_{n-2}Fn​=Fn−1​+Fn−2​ for n≥3n \geq 3n≥3. It is known that ∑k=1nFk=Fn+2−1\sum_{k=1}^n F_k = F_{n+2} - 1∑k=1n​Fk​=Fn+2​−1. What is ∑k=18Fk\sum_{k=1}^8 F_k∑k=18​Fk​?