[seqfan] A091866 Dyck paths and pruning numbers.

[Peter Luschny]

Don Knuth, in the inaugural Philippe Flajolet Lecture
at the Analysis of Algorithms 2014 conference in Paris
discusses, among other things, 'Pruning a Forest' and
a theorem of Mireille Vauchaussade de Chaumont.
In this context Knuth computes the numbers

    1, 13, 81, 275, 500, 432, 128

which appear in row 9 of A091866. Can somebody shed
some light on this connection?

Peter

http://www-cs-faculty.stanford.edu/~uno/flaj2014.pdf