current community
chat
MathOverflow
MathOverflow Meta
your communities
Sign up
or
log in
to customize your list.
more stack exchange communities
company blog
Stack Exchange
Inbox
Reputation and Badges
sign up
log in
tour
help
Tour
Start here for a quick overview of the site
Help Center
Detailed answers to any questions you might have
Meta
Discuss the workings and policies of this site
About Us
Learn more about Stack Overflow the company
Business
Learn more about hiring developers or posting ads with us
MathOverflow
Questions
Tags
Users
Badges
Unanswered
Ask Question
Profile
Activity
Ira Gessel
Meta User
Network Profile
Reputation
5,123
5.1k
3.3k
1.5k
2013
2014
2015
2016
Top tag
co.combinatorics
Next privilege
10,000 Rep.
Access moderator tools
Badges
12
29
Newest
Nice Answer
Next badge
0/1
Custodian
Impact
~
66k
people reached
8 posts edited
0 helpful flags
356 votes cast
summary
answers
questions
tags
badges
favorites
bounties
reputation
all actions
72
Answers
newest
activity
votes
24
The Matrix-Tree Theorem without the matrix
Aug 22 '11 at 18:40
22
Combinatorial meaning of the functional equation for logarithm
Nov 16 '12 at 17:50
17
A particular combinatorial proof of Wilson's theorem
Feb 2 '11 at 3:48
15
Show that this ratio of factorials is always an integer
May 12 '13 at 15:00
15
Does the formal power series solution to $f(f(x))= \sin( x) $ converge?
Nov 11 '10 at 3:53
14
Combinatorial Morse functions and random permutations
Jul 9 '14 at 16:27
14
Extremely messy proofs
Jan 14 '11 at 16:42
13
Number of closed walks on an $n$-cube
Aug 1 '11 at 15:50
13
Use of everywhere divergent generating functions
Nov 13 '10 at 18:50
12
Combinatorial identities
Nov 27 '13 at 16:48
12
The combinatorial interpretation of an identity found in “Primes in tuples I”
Nov 22 '13 at 4:49
11
Exponential of a specific hypergeometric series
Feb 5 '14 at 14:38
11
“MultiCatalan numbers”
Oct 14 '13 at 17:58
11
The proportion between permutations and derangements.
Jun 16 '13 at 19:58
11
Interpolating a sum of binomial coefficients using a sin function
Oct 11 '12 at 18:06
11
Number of integer combinations x_1 < … < x_n ?
Jan 18 '12 at 15:58
10
power series of the reciprocal… does a recursive formula exist for the coefficients.
Jan 26 '11 at 21:22
9
Counting card distributions when cards are duplicated
Feb 18 '11 at 17:40
8
Identity for Power Series and Binomial Coefficients
Jan 26 '15 at 22:22
8
Sign of coefficients
Apr 29 '13 at 13:52
7
Computer package for representation theory of the symmetric group
May 16 '12 at 22:10
7
Number of Dyck paths with prescribed number of edges
Feb 20 '15 at 17:59
7
A recurrence relation on Catalan numbers
Dec 26 '14 at 21:54
7
Counting chains of inclusions
May 30 '14 at 19:25
7
Is there an interesting species whose generating function gives the zigzag numbers?
Mar 26 '14 at 0:14
7
Identifying a special function from its power series
Nov 6 '13 at 17:48
7
The number of lattice paths below y=n/m x for gcd(m,n) = 1
Jun 9 '13 at 21:09
7
Faa di Bruno's formula for inverse functions ?
May 31 '12 at 20:15
7
Sum of products of exponentials and polynomials
Nov 22 '11 at 16:02
7
Implications of a relation on algebraic numbers
Sep 3 '11 at 23:36
MathOverflow works best with JavaScript enabled