Multiplicity fluctuations were investigated in Ar+Sc collisions at 13A, 19A, 30A, 40A, 75A, 150A GeV/c using the NA61/SHINE detector at the SPS. Centrality selection is based on the nucleon-spectator energy in the forward hemisphere as measured by the projectile spectator detector. Preliminary results on the scaled variance ω and the strongly intensive measure Ω were obtained for the multiplicity distribution of all, negatively and positively charged hadrons. Results are discussed and compared with p + p results and Pb+Pb data of NA49 and EPOS 1.99 simulations.