Degree-diameter problem $N(19,6)$
The largest possible number of vertices in a graph of maximum degree $19$ and diameter at most $6$.
Lower bound:
$4024707$
(4,024,707)
Upper bound:
Unknown
Verified bounds
Verified bounds come with a certificate that is checked automatically: a formal proof in Lean, or an explicit construction checked by a program. Submit a certificate.
- Lower bound: None yet
- Upper bound: None yet