a sequence that needs extending

[Dean Hickerson]

I wrote:

> Also, someone proved that  a(n) = o(n^2),  answering Problem 3 on page 97
> of the Stein/Szabo book.  (I've asked Stein for a reference to the paper
> that proves that.)

It's "Tripods do not pack densely" by Alexandre Tiskin, Lecture Notes in
Computer Science, 1858 (2000), 272-280.  It's available on-line at:

    http://www.dcs.warwick.ac.uk/~tiskin/pub/2000/tripods.ps

I haven't figured out exactly what upper bound on a(n) is implied by
Tiskin's proof; I think it's something like  O(n^2 / log(n)^C)  for some
small positive constant C.

I've sent Neil an update for sequence A070214.

Dean Hickerson
dean at math.ucdavis.edu