TITLE: Which knots' stick numbers are twice their crossing numbers?
QUESTION [7 upvotes]: Looking at a table of minimum stick numbers for knots (table here), 
it seems the known upper bound of $2 c(K)$ in terms of the knot crossing number $c(K)$
is realized by the trefoil $3_1$—it requires 6 sticks (see image below) and its crossing number is 3—but not by any other small knot, at least through cursory inspection.
Whence the question in the title: Are there other knots whose minimal stick number reaches the upper
bound of twice its crossing number? This is probably well-known (perhaps well-known to be unknown),
in which case a reference would suffice.  Thanks!



Addendum.
I found a 12-year old answer to my question
in a paper by 
Eric Furstenberg, Jie Lie, and Jodi Schneider [FLS]:

"Thus far, the trefoil is the only knot to realize Negami’s 
  upper bound of $2c[K]$ on the 
  stick number. 
  Do other such knots exist, and if so, what are their similarities to the 
  trefoil?"

If anyone knows of more recent information, I would appreciate
hearing of it.  Thanks!
[FLS]
"Stick Knots."
Eric Furstenberg, Jie Lie, and Jodi Schneider.
Chaos, Solitons & Fractals, Vol. 9, No. 4-5, pp. 561-568, 1998.
Elsevier link

REPLY [9 votes]: I just read the following paper, where an answer can be found:
Youngsik Huh, Seungsang Oh, An upper bound on stick number of knots, J. Knot Theory Ram. 20 (2011), no. 5, 741–747, doi: 10.1142/S0218216511008966, arXiv: 1512.03592. 
There it is shown that the trefoil is the only knot whose stick number equals twice its crossing number. 
This is a consequence of the authors' main result (Thm. 1.1), which states that any nontrivial knot $K$ satisfies $s(K)\leq \frac{3}{2}(c(K)+1)$ (thus improving Negami's upper bound).