Let $s(n)$ be the number of 1's in the binary representation of $n$. Find the number of ordered pairs of integers $(a, b)$ with $0 \leq a < 64, 0 \leq b < 64$ and $s(a+b) = s(a) + s(b) - 1$.

Let's think step by step and output the final answer within \boxed{}.
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