sum-over-states

{\sum _{n=0}}^{k}(n+1)(n+2)={(k+1)(k+2)(k+3) \over 3}} 對所有的整數k，給出了以下的幻數2,8,20,40,70,112... 前六個能級是 level 0: 2 states (l = 0) = 2. level 1: 6 states (l

q ˙ i + ∂ r ∂ t {\displaystyle \mathbf {v} ={\frac {d\mathbf {r} }{dt}}=\sum _{i}\ {\frac {\partial \mathbf {r} }{\partial q_{i}}}{\dot {q}}_{i}+{\frac

\rangle =e^{-{|\alpha |^{2} \over 2}}\sum _{n=0}^{\infty }{\alpha ^{n} \over {\sqrt {n!}}}|n\rangle =e^{-{|\alpha |^{2} \over 2}}e^{\alpha {\hat {a}}^{\dagger

（原始内容存档于2014-10-05）.  U.S. Metro Economies (note CSA 2012 GMP total includes sum of New York, Bridgeport, New Haven, Scranton, Trenton, Poughkeepsie, and

in which victory went sometimes to Koryŏ, sometimes to the Khitan, but in sum were indecisive.  Ebrey, Patricia Buckley; Walthall, Anne, Pre-Modern East