1+3+5+.+(2n-5)+(2n-3)+(2n-1)+(2n+1)+(2n+3)
问题描述:
1+3+5+.+(2n-5)+(2n-3)+(2n-1)+(2n+1)+(2n+3)
自然数
答
1+3+5+.+(2n-5)+(2n-3)+(2n-1)+(2n+1)+(2n+3)
= [1+(2n+3)](n+2) / 2
= (n+2)^2