Math Gold Medalist

Lor

2023 AMC 10B 

Problem 6

Let $L_1 = 1$$L_2 = 3$, and $L_{n+2} = L_{n+1}+L_n$ for $n \geq 1$. How many terms in the sequence $L_1, L_2, L_3, \cdots, L_{2023}$ are even?

$\textbf{(A) }673\qquad\textbf{(B) }1011\qquad\textbf{(C) }675\qquad\textbf{(D) }1010\qquad\textbf{(E) }674$

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   Solution