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Counting & ProbabilityHardDistributions: Stars & Bars and Integer Solutions

Distributions: Stars & Bars and Integer Solutions · Hard problem

How many nondecreasing integer sequences 1≤a1≤a2≤a3≤a4≤a5≤a6≤41\le a_1\le a_2\le a_3\le a_4\le a_5\le a_6\le 4 are there?