Consider the expansion of (x1+x2+x3+x4)8(x_1 + x_2 + x_3 + x_4)^8(x1+x2+x3+x4)8. How many distinct terms are in the expansion?
(8+4−14−1)\binom{8+4-1}{4-1}(4−18+4−1)
(113)\binom{11}{3}(311)
165165165
484^848