Upper Hessenberg matrices with subdiagonal entries fixed at 1 and all other entries from the set {-1, +1}.
Characteristic Polynomials
Data files have been temporarily removed due to unexpected costs, if you would like access to the characteristic polynomial data files please contact me at sthornt7@uwo.ca .
Download all characteristic polynomials:
Minimal Polynomials
Download all minimal polynomials:
Properties
Download all properties: Properties.csv
Characteristic Polynomials
Matrix Size
Number of Matrices
Number of Characteristic Polynomials
Number of Minimal Polynomials
Number of Non-Derogatory Matrices
Maximum Characteristic Height
OEIS
A006125
2x2
8
6
6
8
2
3x3
64
32
32
64
5
4x4
1,024
289
289
1,024
12
5x5
32,768
4,958
4,958
32,768
28
6x6
2,097,152
162,059
162,059
2,097,152
66
7x7
268,435,456
10,318,948
168
8x8
68,719,476,736
1,279,227,671
416
Eigenvalues
Matrix Size
Number of Distinct Eigenvalues
Number of Distinct Real Eigenvalues
Number of Distinct Purely Complex Eigenvalues
Number of Distinct Jordan Canonical Forms
OEIS
2x2
9
5
4
6
3x3
65
29
36
32
4x4
689
233
456
289
5x5
20,565
7,363
13,202
4,958
6x6
887,539
299,477
588,062
162,059
7x7
8x8
Rank
Matrix Size
Number of Singular Matrices
Number of Non-Singular Matrices
Number of Rank 1 Matrices
Number of Rank 2 Matrices
Number of Rank 3 Matrices
Number of Rank 4 Matrices
Number of Rank 5 Matrices
Number of Rank 6 Matrices
Number of Rank 7 Matrices
Number of Rank 8 Matrices
OEIS
2x2
4
4
4
4
3x3
24
40
0
24
40
4x4
304
720
0
0
304
720
5x5
7,648
25,120
0
0
0
7,648
25,120
6x6
383,680
1,713,472
0
0
0
0
383,680
1,713,472
7x7
38,422,400
230,013,056
8x8
7,683,485,440
61,035,991,296
Determinant
Matrix Size
Number of Distinct Determinants
Maximum Determinant
Number of Unimodular Matrices
OEIS
A000079
2x2
3
2
0
3x3
5
4
0
4x4
9
8
0
5x5
17
16
0
6x6
33
32
0
7x7
65
64
0
8x8
129
128
0
Miscellaneous
Matrix Size
Number of Normal Matrices
Number of Rhapsodic Matrices
Number of Nilpotent Matrices
Number of Totally Unimodular Matrices
Number of Type I Stable Matrices
Number of Type II Stable Matrices
OEIS
2x2
2
3x3
0
4x4
0
5x5
0
6x6
324
7x7
0
8x8
0