We demonstrate that by using a pair of hybrid photodetectors, it is possible to quantify the photon-number correlation coefficient between the components of a classical state described by non-trivial statistics and by a non-Gaussian Wigner function. The measurements, performed in the quite unexplored mesoscopic domain (up to 100 photons incident onto the detector), are in good agreement with the theoretical predictions, and thus open the possibility of performing further tests on this exotic state for its application in the field of quantum information.