We present an improved parallel algorithm for the enumeration of fixed
benzenoids B_h containing h hexagonal cells. We can thus extend the enumeration
of B_h from the previous best h=35 up to h=50. Analysis of the associated
generating function confirms to a very high degree of certainty that Bh∼Aκh/h and we estimate that the growth constant κ=5.161930154(8) and the amplitude A=0.2808499(1).Comment: 14 pages, 6 figure