A262673 Number of pointed trees on normal pointed multisets of weight n.

1, 3, 34, 615, 15410, 494018

Offset

1,2

Comments

A pointed multiset is normal if its entries span an initial interval of positive integers.

Links

Table of n, a(n) for n=1..6.

Example

The a(2) = 3 pointed trees are 1[1 1], 1[1 2], 2[1 2].
The a(3) = 34 pointed trees of the form rootpoint[pointedbranch ... pointedbranch] are:
1[1 1[1 1]], 1[1[1 1] 1], 1[1 1 1],
1[1 2[2 2]], 1[1[1 2] 2], 1[1 2 2],
2[1 2[2 2]], 2[1[1 2] 2], 2[2 2[1 2]], 2[2[1 2] 2], 2[1 2 2],
1[1 1[1 2]], 1[1 2[1 2]], 1[1[1 1] 2], 1[1[1 2] 1], 1[1 1 2],
2[1 2[1 2]], 2[1[1 1] 2], 2[1 1 2],
1[1 2[2 3]], 1[1 3[2 3]], 1[1[1 2] 3], 1[1[1 3] 2], 1[1 2 3],
2[1 2[2 3]], 2[1[1 3] 2], 2[2 3[1 3]], 2[2[1 2] 3], 2[1 2 3],
3[1 3[2 3]], 3[1[1 2] 3], 3[2 3[1 3]], 3[2[1 2] 3], 3[1 2 3].

Crossrefs

Cf. A053492, A052894, A262671.

Sequence in context: A337388 A317653 A143638 * A365040 A126753 A047794

Adjacent sequences: A262670 A262671 A262672 * A262674 A262675 A262676

Keyword

nonn,more

Author

Gus Wiseman, Sep 26 2015

Status

approved