`nRootedShapes`

and `nUnrootedShapes`

give the number of (un)rooted binary
trees on *n* unlabelled leaves.

```
nRootedShapes
nUnrootedShapes
```

An object of class `integer64`

of length 55.

An object of class `integer64`

of length 60.

`nRootedShapes`

corresponds to the Wedderburn-Etherington numbers,
OEIS A001190

`nUnrootedShapes`

is OEIS A000672