So for each vertex \( v \), the number of paths of length 2 with center \( v \) is \( inom{\deg(v)}{2} \), and each such path \( u-v-w \) uses edges \( uv \) and \( vw \), both in \( E \). Then the trio \( \{u,v,w\} \) has exactly two close pairs (if no other edge), and since \( u \) and \( w \) are not necessarily connected, it’s exactly 2.

Fri, 08 May 2026 10:59:17 +0000

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