A338728 a(n) = number of binary increasing trees with labels from {1,2,...n} which are beth-avoiding.

1, 1, 2, 5, 15, 53, 217, 1013

Offset

0,3

Comments

"beth" should be written as the Hebrew letter of that name.

Links

Table of n, a(n) for n=0..7.

Marilena Barnabei, Flavio Bonetti, Niccolò Castronuovo, Matteo Silimbani, Permutations avoiding a simsun pattern, The Electronic Journal of Combinatorics (2020) Vol. 27, Issue 3, P3.45.

Formula

See Barnabei et al. (2020), Th. 2, for a recurrence.

Crossrefs

Sequence in context: A328432 A337850 A125280 * A022493 A348580 A284729

Adjacent sequences: A338725 A338726 A338727 * A338729 A338730 A338731

Keyword

nonn,more

Author

N. J. A. Sloane, Dec 01 2020.

Status

approved