What would happen to an organism's total number of chromosomes every generation if mitosis produced gametes?

if mitosis produce gametes then after fertilization the chromosome number will double than parent and so on. in each generation chromosome sets which are 2n normally ensuring new generation should exactly similar to parent generation. but the case will change when gametes are not haploid. these will be 4n, in next generation it will be 8n, and in next it will be 16n and so on.

Explanation:

meiosis is the first to occur after the nuclei of opposite of opposite mating types fuse