Inequalities for ranks of partitions and the first moment of ranks and cranks of partitions

We prove two monotonicity properties of N(m,n)$N(m,n)$, the number of partitions of n with rank m. They are (i) for any nonnegative integers m and n,

N(m,n)?N(m+2,n),$N(m,n)?N(m+2,n),$

and, (ii) for any nonnegative integers m and n   such that n?12$n?12$, n≠m+2$n\ne m+2$,

N(m,n)?N(m,n−1).$N(m,n)?N(m,n-1).$

G.E. Andrews, B. Kim, and the first author introduced ospt(n)$\mathrm{ospt}(n)$, a function counting the difference between the first positive rank and crank moments. They proved that ospt(n)>0$\mathrm{ospt}(n)>0$. In another article, K. Bringmann and K. Mahlburg gave an asymptotic estimate for ospt(n)$\mathrm{ospt}(n)$. The two monotonicity properties for N(m,n)$N(m,n)$ lead to stronger inequalities for ospt(n)$\mathrm{ospt}(n)$ that imply the asymptotic estimate.