Determinants and Their Applications in Mathematical Physics

(Chris Devlin) #1
A.2 Permutations 307

Sij

j

i 12345

1 1

2 11

3 131

4 1761

5 11525101

Further values are given by Abramowitz and Stegun. Stirling numbers ap-


pear in Section 5.6.3 on distinct matrices with nondistinct determinants


and in Appendix A.6.


The matricessn(x) andSn(x) are defined as follows:

sn(x)=

[

sijx

i−j

]

n

=

      

1

−x 1

2 x

2
− 3 x 1

− 6 x

3
11 x

2
− 6 x 1

24 x

4
− 50 x

3
35 x

2
− 10 x 1

...............................

       n

,

Sn(x)=

[

Sijx

i−j

]

n

=

      

1

x 1

x
2
3 x 1

x
3
7 x
2
6 x 1

x
4
15 x
3
25 x
2
10 x 1

.........................

       n

.

A.2 Permutations


Inversions, the Permutation Symbol


The firstnpositive integers 1, 2 , 3 ,...,n, can be arranged in a linear se-


quence inn! ways. For example, the first three integers can be arranged in


3! = 6 ways, namely


123

132

213

231

312

321

LetNndenote the set of the firstnintegers arranged in ascending order of


magnitude,


Nn=

{

123 ···n

}

,
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