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{\bf C. Merino}
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{\bf The Number of 0-1-2 Increasing Trees as Two Different Evaluations of the Tutte Polynomial of a Complete Graph}
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If $T_{n}(x,y)$ is the Tutte polynomial of the complete graph $K_n$,
we have the equality $T_{n+1}(1,0)=T_{n}(2,0)$. This has an almost
trivial proof with the right combinatorial interpretation of
$T_{n}(1,0)$ and $T_{n}(2,0)$. We present an algebraic proof of a
result with the same flavour as the latter: $T_{n+2}(1,-1)=T_n(2,-1)$,
where $T_{n}(1,-1)$ has the combinatorial interpretation of being the
number of 0--1--2 increasing trees on $n$ vertices.
\bye