A300128 - OEIS

A300128

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

0, 1, 1, 1, 5, 9, 17, 55, 122, 289, 828, 2037, 5239, 14578, 37942, 101307, 281041, 755726, 2062288

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,5

COMMENTS

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".

LINKS

Table of n, a(n) for n=0..18.

Olivier Bodini, Paul Tarau, On Uniquely Closable and Uniquely Typable Skeletons of Lambda Terms, arXiv:1709.04302 [cs.PL], 2017.

CROSSREFS

Cf. A000108, A001006, A135501.

Sequence in context: A146067 A336139 A295627 * A334993 A262484 A228956

Adjacent sequences: A300125 A300126 A300127 * A300129 A300130 A300131

KEYWORD

nonn,more

AUTHOR

Michael De Vlieger, Feb 25 2018

STATUS

approved