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1 vote
0 answers
60 views

Generating Function for Modified Multinomial Coefficients

The multinomial coefficients can be used to expand expressions of the form ${\left( {{x_1} + {x_2} + {x_3} + ...} \right)^n}$ in the basis of monomial symmetric polynomials (MSP). For example, $$\...
Bear's user avatar
  • 51
1 vote
1 answer
143 views

Generating function of ordered odd partitions of $n$.

Let the number of ordered partitions of $n$ with odd parts be $f(n)$. Find the generating function $f(n)$ . My try : For $n=1$ we have $f(1)=1$, for $n=2$, $f(2)=1$, for $n=3$, $f(3)=2$, for $n=4$, $...
user avatar
7 votes
1 answer
167 views

How to prove the following resummation identity for Erdős–Borwein constant?

Question: How to prove $$\sum_{m=1}^{\infty}\left(1-\prod_{j=m}^{\infty}(1-q^j)\right) = \sum_{n=1}^{\infty}\frac{q^n}{1-q^n} \tag{1}$$ for all $q \in \mathbb{C}$ such that $\left|q\right| < 1$? ...
Fiktor's user avatar
  • 3,132
1 vote
2 answers
193 views

What is the closed form solution to the sum of inverse products of parts in all compositions of n?

My question is exactly as in the title: What is the generating function or closed form solution to the sum of inverse products of parts in all compositions of $n$? This question was inspired by just ...
Danyu Bosa's user avatar
5 votes
3 answers
1k views

Proving that odd partitions and distinct partitions are equal

I am working through The Theory of Partitions by George Andrews (I have the first paperback edition, published in 1998). Corollary 1.2 is a standard result that shows that the number of partitions of $...
seeker_after_truth's user avatar
0 votes
1 answer
28 views

How does one handle series generating functions with multiple equals signs?

How would somebody walk through this equation? I'm looking for $q(n)$. If I'm given an input of 10, for example, how would this play out? The two equals signs is throwing me off. Does the result of ...
camstar915's user avatar
2 votes
0 answers
192 views

Is there a generating function for this sequence?

The sequence is: 1, 2, 3, 5, 8, 12, 18, 25, 35, 50, 69, 93, 126, 167, 220, 290, 377, 486, 627, 800, 1017, 1290, 1623, 2032, 2542, 3161, 3917, 4843,... It is related to partitions of $n$. It is a ...
jnthn's user avatar
  • 351
0 votes
0 answers
181 views

A generating function $G(x)=-\frac{\frac{1}{x^5}(1+\frac{1}{x})(1-\frac{1}{x^2})}{((1-\frac{1}{x})(1-\frac{1}{x^3}))^2}$ related to partitions of $6n$

Fix a sequence $a_n={n+2\choose 2}$ of triangular numbers with the initial condition $a_0=1$,such that $1,3,6,10,15,21,\dots$ given by $F(x)=\frac{1}{(1-x)^3}=\sum_{n=0}^{\infty} a_n x^n\tag1$ ...
Nicco's user avatar
  • 2,813
8 votes
3 answers
693 views

How to prove it? (one of the Rogers-Ramanujan identities)

Prove the following identity (one of the Rogers-Ramanujan identities) on formal power series by interpreting each side as a generating function for partitions: $$1+\sum_{k\geq1}\frac{z^k}{(1-z)(1-z^2)...
Geeeee's user avatar
  • 825