Abstract:
Let p(n) denote the number of unrestricted partitions of n. For i=0, 2, let p[i](n) denote the number of partitions pi of n such that O(pi) - O(pi') = i mod 4. Here O(pi) denotes the number of odd parts of the partition pi and pi' is the conjugate of pi. Recently, R. Stanley [13], [14] derived an infinite product expansion for the generating function of p[0](n)-p[2](n). Recently, H. Swisher[15] employed the circle method to show that (i) limit[n->oo] p[0](n)/p(n) = 1/2 and that for sufficiently large n 2 p[0](n) > p(n), if n=0,1 mod 4, (ii) 2 p[0](n) < p(n), otherwise. In this paper we study the even/odd dissection of the Stanley product, and show how to use it to prove (i) and (ii) with no restriction on n. Moreover, we establish the following new result |p[0](2n) - p[2](2n)| > |p[0](2n+1) - p[2](2n+1)|, n>0. Two proofs of this surprising inequality are given. The first one uses the Gollnitz-Gordon partition theorem. The second one is an immediate corollary of a new partition inequality, which we prove in a combinatorial manner. Our methods are elementary. We use only Jacobi's triple product identity and some naive upper bound estimates.
The url of this page is http://www.math.ufl.edu/~frank/abstracts/stanley3.html.
Created by
Francis Garvan
(frank@math.ufl.edu) on
Saturday, September 25, 2004.
Last update made Mon Dec 19 19:33:28 EST 2005.