Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #7 Feb 27 2018 03:40:27
%S 0,1,2,3,10,34,98,339,1263,4626,18099,73782,306295,1319660,5844714,
%T 26481404,123172740
%N Number of Motzkin trees that are "typable closed terms".
%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 0,3
%A _Michael De Vlieger_, Feb 25 2018