In this paper, we obtain infinitely many non-trivial identities and
inequalities between full rank differences for 2-marked Durfee symbols, a
generalization of partitions introduced by Andrews. A certain strict
inequality, which almost always holds, shows that identities for Dyson's rank,
similar to those proven by Atkin and Swinnerton-Dyer, are quite rare.
We investigate here sums of triangular numbers $f(x):=\ssum{i}{} b_i T_{x_i}$
where $T_n$ is the $n$-th triangular number. We show that, fixing $b_i\geq 0$,
$f(x)$ represents every nonnegative integer if and only if it represents 1, 2,
4, 5, and 8, with the standard application to sums of odd squares $\ssum{i}{}
b_i (2x_i+1)^2$. Moreover, we show that no finite subset will suffice if "cross
terms" are included, in turn showing that there is no overarching finiteness
theorem which generalizes from positive definite quadratic forms to totally
positive quadratic polynomials.
In 1997 Ken Ono and K. Soundararajan [Invent. Math. 130(1997)] proved that
under the generalized Riemann hypothesis any positive odd integer greater than
2719 can be represented by the famous Ramanujan form $x^2+y^2+10z^2$,
equivalently the form $2x^2+5y^2+4T_z$ represents all integers greater than
1359, where $T_z$ denotes the triangular number $z(z+1)/2$.
The average value of log s(n)/n taken over the first N even integers is shown
to converge to a constant lambda when N tends to infinity; moreover, the value
of this constant is approximated and proven to be less than 0. Here s(n) sums
the divisors of n less than n. Thus the geometric mean of s(n)/n, the growth
factor of the function s, in the long run tends to be less than 1. This could
be interpreted as probabilistic evidence that aliquot sequences tend to remain
bounded.
We prove new equidistribution results for Galois orbits of Heegner points
with respect to reduction maps at inert primes. The arguments are based on two
different techniques: primitive representations of integers by quadratic forms
and distribution relations for Heegner points.