Distance travel in a particular sec have the same dimension of velocity. 

$\mathrm{u} \mathrm{is} \mathrm{velocity} \mathrm{and}$ $\frac{\mathrm{a}}{2}\left(2\mathrm{n}-1\right) \mathrm{this} \mathrm{is} \mathrm{acceleration} \times \mathrm{time} \mathrm{also} \mathrm{gives} \mathrm{the} \mathrm{dimension} \mathrm{of} \mathrm{velocity}$.

so equation is dimensionally correct but numerically it is not possible to infer that it is correct or not as the value of constant cannot be verified dimensionally.