Counterexamples to a conjecture of Merker on 3-connected cubic planar graphs with a large cycle spectrum gap

Carol T. Zamfirescu

Published 2020-08-30Version 1

Merker conjectured that if $k \ge 2$ is an integer and $G$ a 3-connected cubic planar graph of circumference at least $k$, then the set of cycle lengths of $G$ must contain at least one element of the interval $[k, 2k+2]$. We here prove that for every even integer $k \ge 6$ there is an infinite family of counterexamples.