Hušek–Šámal's exponential circuit double cover conjecture

Let $G$ be a $2$-connected cubic graph on $n$ vertices. A circuit double cover (CiDC) is a finite family of connected $2$-regular subgraphs of $G$ such that every edge belongs to exactly two members of the family.

Hušek–Šámal's conjecture. The graph $G$ has at least

$$2^{n/2-1}$$

CiDCs.

This is a quantitative strengthening of the cycle double cover problem. The bound is proved in the source for $2$-connected $3$-edge-colorable cubic graphs and is known to be tight for Klee graphs, while the general conjecture remains open.