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Number of Motzkin trees that are "typable closable skeletons".
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%I #8 Feb 27 2018 03:40:30

%S 0,1,1,1,5,9,17,55,122,289,828,2037,5239,14578,37942,101307,281041,

%T 755726,2062288

%N Number of Motzkin trees that are "typable closable skeletons".

%C From the Bodini-Tarau paper: a Motzkin skeleton is called "typable" if "it exists at least one simply-typed closed lambda term having it as its skeleton".

%H Olivier Bodini, Paul Tarau, <a href="https://arxiv.org/abs/1709.04302">On Uniquely Closable and Uniquely Typable Skeletons of Lambda Terms</a>, arXiv:1709.04302 [cs.PL], 2017.

%Y Cf. A000108, A001006, A135501.

%K nonn,more

%O 0,5

%A _Michael De Vlieger_, Feb 25 2018