∑ m = 1 ∞ ∑ n = 1 ∞ m 2 n 3 m ( m 3 n + n 3 m ) {\displaystyle \sum _{m=1}^{\infty }\sum _{n=1}^{\infty }{\frac {m^{2}\,n}{3^{m}\left(m\,3^{n}+n\,3^{m}\right)}}}
W = J s = N·m s = kg·m 2 s 3 = V·A {\displaystyle {\mbox{ W}}={\frac {\mbox{J}}{\mbox{s}}}={\frac {\mbox{N·m}}{\mbox{s}}}={\frac {{\mbox{kg·m}}^{2}}{{\mbox{s}}^{3}}}={\mbox{ V·A}}}
