Duscuss the below:
Create a list that shows how many times sku1 was sold with sku2, with sky 3, with sku4, etc. through sku9 with sku10. This will show the combination of two products that is bought most frequently together.
Then do the same but for sku1, sku2, sku3; then sku1, sku2, & sku4, then for sku1, sku2, and sku5, etc. This will show the combination of three products that are bought together most frequently.
Then do the same for the combination of four skus.