How many possible combinations are there

Total possible combinations are 12869.
It is given that you can order maximum of 8 items and you are allowed to have less than 8 items. Also, the order of purchase does not matter. Let's create a table for ordering total N items using X products.
Items
Ordered
(N) Products Used (X)
1 2 3 4 5 6 7 8
1 1 - - - - - - -
2 1 1 - - - - - -
3 1 2 1 - - - - -
4 1 3 3 1 - - - -
5 1 4 6 4 1 - - -
6 1 5 10 10 5 1 - -
7 1 6 15 20 15 6 1 -
8 1 7 21 35 35 21 7 1
Total (T) 8 28 56 70 56 28 8 1
Ways to choose
X products from
8 products (W) 8C1 8C2 8C3 8C4 8C5 8C6 8C7 8C8
Total combinations
(T*W) 64 784 3136 4900 3136 784 64 1
Thus, total possible combinations are
= 64 + 784 + 3136 + 4900 + 3136 + 784 + 64 + 1
= 12869