[seqfan] Re: Problem with consistency of A086581

[Maximilian Hasler]

Note the line
Cf. a(n)=A025242(n+1)=A082582(n+1).

This means that the same sequence is there 3 times.
I suggest merging the two A08xxxx into A025242.
Also note that the convention about semilength seems to be the same in
[1st comment on] sequence A025242 (maybe?).

PS: tried to submit this via the pink box, but got an error
"The server broke trying to handle your request. The error has been
reported. Sorry. "

Maximilian




On Thu, Mar 24, 2011 at 10:22 PM, David Scambler <dscambler at bmm.com> wrote:
> Sequence A086581<https://oeis.org/A086581> has inconsistent name/offset/data/formula/example.
>
> The name is "Number of Dyck paths of semilength n with no UUDD" with offset 0,
> commencing 1, 1, 2, 5, 13,...
>
> This would be correct if any of the following changes were made:
>
>
> 1)      Name change to "Number of Dyck paths of semilength n with no DDUU"
>
> 2)      Offset change to 1, or
>
> 3)      Data change to 1, 1, 1, 2, 5, 13,...
>
> However the formulas from Paul Barry matche the data and offset,
> whereas the example from  Emeric Deutsch matches what the sequence claims to be.
>
> The easiest fix-all would be to change the name to
> "Number of Dyck paths of semilength n+1 with no UUDD" but that is not as
> elegant as the existing name.
>
> Several changes need to be made. Any suggestions?
>
> dave
>
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