[seqfan] Re: A005700 Number of Dyck paths: a(n) = <not a Dyck path>

[Charles Greathouse]

Good catch.

We have several hundred sequences relating to (or purporting to relate
to) Dyck paths; do you think this (mis)use of terminology is common?

Charles Greathouse
Analyst/Programmer
Case Western Reserve University

On Thu, Jan 27, 2011 at 11:46 PM, David Scambler <dscambler at bmm.com> wrote:
> "A005700        Number of Dyck paths: a(n) = number of walks of 2n unit steps north,
> east, south, or west starting and ending at the origin and confined to the first octant."
>
> It seems to me that the phrase "Dyck paths" immediately followed by a definition
> that is not the definition of a Dyck path is invalid.
>
> The definition is that of a closed first octant path, not a Dyck path.
> At best, the references refer to pairs of Dyck paths.
>
> To be sure there are generalizations of Dyck paths, but these are clearly distinguished by their names, e.g.
> "grand Dyck path", "Dyck path of knight moves" etc.
>
> Maybe "Number of lattice paths" would be better.
>
> dave
>
>
>
>
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