Degree-diameter problem $N(15,9)$
The largest possible number of vertices in a graph of maximum degree $15$ and diameter $9$.
Lower bound:
$1171998164$
(1,171,998,164)
Upper bound:
Unknown
Updates
-
2008
Lower bound: $1171998164$
(1,171,998,164)
Loz, E., & Sirán, J. (2008). New record graphs in the degree-diameter problem. Australasian Journal of Combinatorics, 41, 63.
[via Table of the largest known graphs of a given diameter and maximal degree - Wikipedia]