This is LaTeX code:

[latex]
\bigstar=\displaystyle\sum_{k=3}^\infty Q^k\left(\frac{q}{np}\right)^\frac{k}{2}=\sum_{k=3}^\infty\left(Q\left(\frac{q}{np}\right)^\frac{1}{2}\right)^k=\spadesuit
[/latex]