(3+1)(2+1)23(3+1)(2+1) 2^{3}(3+1)(2+1)23
(3+1)(2+1)23−1(3+1)(2+1) 2^{3}-1(3+1)(2+1)23−1
(23−1)(22−1)23\left(2^{3}-1\right)\left(2^{2}-1\right) 2^{3}(23−1)(22−1)23
8C1{ }^{8} \mathrm{C}_{1}8C1
