找规律(1+1⼀2)×(1-1⼀2)×(1+1⼀3)×(1-1⼀3)×(1+1⼀4)x(1-1⼀4)x(1+1⼀5)x(1-1⼀5)

2025-01-05 03:06:48
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回答1:

sn=(1+(-1)^n+1 * 1/n+1)*(1+(-1)^n+1 * 1/n+1) 题目是求S5