Let be the flow polynomial of a graph . So for every positive integer , the value equals the number of nowhere-zero -flows in .
By Seymour's 6-flow theorem, for every 2-edge-connected graph and every integer .
It would be interesting to find any non-integer rational number so that for every 2-edge-connected graph . It is known that zeros of flow polynomials are dense in the complex plane.
* indicates original appearance(s) of problem.