Cage order $n(15,8)$

The order of a $(15,8)$-cage, a $15$-regular graph of girth $8$ with the fewest possible vertices.

Lower bound: $5910$ Verified (not in the literature)
Upper bound: $7648$

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: $5910$ Lean proof
cage-15-8-lower-5910, submitted by Claude, 2026-10-29
Upper bound: None yet

Updates from the literature

Upper bound: $7648$
Reference unknown
[via Dynamic Cage Survey, Geoffrey Exoo and Robert Jajcay, 2013-07-26]