HMMT 二月 2001 · 冲刺赛 · 第 36 题
HMMT February 2001 — Guts Round — Problem 36
题目详情
英文原题
- [4] Count the number of sequences 1 ≤ a ≤ a ≤ · · · ≤ a of integers with a ≤ i
1 2 5 ifor all i .
解析
英文解析
- [4] Count the number of sequences 1 ≤ a ≤ a ≤ · · · ≤ a of integers with a ≤ i
1 2 5 ifor all i .
Solution: C (number of terms) = C (5) = 42 .