Skip to main content
Search type Search syntax
Tags [tag]
Exact "words here"
Author user:1234
user:me (yours)
Score score:3 (3+)
score:0 (none)
Answers answers:3 (3+)
answers:0 (none)
isaccepted:yes
hasaccepted:no
inquestion:1234
Views views:250
Code code:"if (foo != bar)"
Sections title:apples
body:"apples oranges"
URL url:"*.example.com"
Saves in:saves
Status closed:yes
duplicate:no
migrated:no
wiki:no
Types is:question
is:answer
Exclude -[tag]
-apples
For more details on advanced search visit our help page
Results tagged with
Search options not deleted user 48831

A generating function is a way of encoding an infinite sequence of numbers by treating them as the coefficients of a formal power series. Tag questions involving generating functions in this.

1 vote
Accepted

Asymptotics of coefficients of implicitely defined generating function

Since $a_0\neq 0$ there is (by the (formal) Lagrange theorem) a unique formal power series $x=x(z)$ solving $x={z \over A^3(x)}$, and $A(x(z))=B(z)$ because $A(x)=B(x\,A^3(x))$. Expanding $A(x)$ using …
esg's user avatar
  • 3,255
2 votes
Accepted

Monotonicity of the sum of coefficients of a family of generating functions

Your conjecture is true. First, observe that \begin{align*} K_{w+1}(z)&=(1+z)\,K_w(z) & \mbox{ if } w \mbox{ is odd, }\\ K_{w+1}(z)&=(1+z)\,K_w(z) +\frac{1}{2}{w\choose \frac{w}{2}}z^{w/2}(1-z) & …
esg's user avatar
  • 3,255
1 vote
Accepted

Total progeny of a Galton-Watson branching process - standard textbook question

The answer above is fine, nevertheless I make some hopefully useful supplementary remarks (the first two essentially reformulating Did's answer) (1) It is well known (see e.g. Feller I, 3rd ed., p.29 …
esg's user avatar
  • 3,255
1 vote
Accepted

Multivariate Generating Function Related to Lambert $W$ Function and Counting Trees with a C...

The asymptotic distribution of the number of nodes at maximal height in a random tree is known. The following was known as "Wilf's conjecture" (H. S. Wilf stated it in 1991, evidently unaware of the …
esg's user avatar
  • 3,255