A124778 Number of unlabeled unordered rooted forests associated with compositions in standard order.

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 2, 1, 2, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1

Offset

0,11

Comments

The standard order of compositions is given by A066099.

The k-th term of the composition is the number of objects at height k; in particular, the first term is the number of trees.

Links

Table of n, a(n) for n=0..31.

Example

Composition number 11 is 2,1,1; there is only 1 forest associated with this (shown below), so a(11) = 1.
O..
|..
O..
|..
O.O
The table starts:
1
1
1 1
1 1 1 1
1 1 2 1 1 1 1 1

Crossrefs

Cf. A066099, A011782 (row lengths), A000081 (row sums).

Sequence in context: A356428 A158819 A031279 * A037831 A188169 A107039

Adjacent sequences: A124775 A124776 A124777 * A124779 A124780 A124781

Keyword

more,nonn,tabf

Author

Franklin T. Adams-Watters, Nov 06 2006

Status

approved