摘要: ∑ni=0i2=(n2+n)(2n+1)6 $\sum_{i=0}^n i^2 = \frac{(n^2+n)(2n+1)}{6}$log2x $\log_2 x$α,β,…,ω \alpha, \beta, …, \omegaΓ,Δ,…,Ω:Γ,Δ,…,Ω \Gamma,... 阅读全文
posted @ 2016-06-07 16:34 shugen 阅读(142) 评论(0) 推荐(0) 编辑