An inversion of a permutation o is a pair i < j such that oi>oj. Let I(n, k) denote the number of permutations in Sn with k inversions Prove the Identity below n k=0 I(n, k)æk = 1(1+x)(1+x+x²)...(1 +x+ ... +xn−¹) +x²-1) We often denote [m]x = 1+x+...+xm-1, and denote the value on the right hand side [n]!, the x-analogue of n! (this is because setting a = 1 recovers n!).

Advanced Engineering Mathematics
10th Edition
ISBN:9780470458365
Author:Erwin Kreyszig
Publisher:Erwin Kreyszig
Chapter2: Second-order Linear Odes
Section: Chapter Questions
Problem 1RQ
icon
Related questions
Question

Discrete Math

i=0
An inversion of a permutation o is a pair i < j such that σį > σj. Let
I(n, k) denote the number of permutations in Sn with k inversions Prove the Identity below
n
ΣI(n, k)æk = 1(1+x)(1+x+x²)... (1+x+ ... + xn−¹)
k=0
We often denote [m]x = 1+x+...+xm-1, and denote the value on the right
hand side [n]!, the x-analogue of n! (this is because setting x = 1 recovers n!).
Transcribed Image Text:i=0 An inversion of a permutation o is a pair i < j such that σį > σj. Let I(n, k) denote the number of permutations in Sn with k inversions Prove the Identity below n ΣI(n, k)æk = 1(1+x)(1+x+x²)... (1+x+ ... + xn−¹) k=0 We often denote [m]x = 1+x+...+xm-1, and denote the value on the right hand side [n]!, the x-analogue of n! (this is because setting x = 1 recovers n!).
Expert Solution
steps

Step by step

Solved in 5 steps with 21 images

Blurred answer
Similar questions
Recommended textbooks for you
Advanced Engineering Mathematics
Advanced Engineering Mathematics
Advanced Math
ISBN:
9780470458365
Author:
Erwin Kreyszig
Publisher:
Wiley, John & Sons, Incorporated
Numerical Methods for Engineers
Numerical Methods for Engineers
Advanced Math
ISBN:
9780073397924
Author:
Steven C. Chapra Dr., Raymond P. Canale
Publisher:
McGraw-Hill Education
Introductory Mathematics for Engineering Applicat…
Introductory Mathematics for Engineering Applicat…
Advanced Math
ISBN:
9781118141809
Author:
Nathan Klingbeil
Publisher:
WILEY
Mathematics For Machine Technology
Mathematics For Machine Technology
Advanced Math
ISBN:
9781337798310
Author:
Peterson, John.
Publisher:
Cengage Learning,
Basic Technical Mathematics
Basic Technical Mathematics
Advanced Math
ISBN:
9780134437705
Author:
Washington
Publisher:
PEARSON
Topology
Topology
Advanced Math
ISBN:
9780134689517
Author:
Munkres, James R.
Publisher:
Pearson,