Atoms in Block Monoids over Small Abelian Groups
The following table lists all abelian groups of order at most 101, organized by order (row) and rank (column). Each entry is a link to an ascii text file that reports the number of atoms of each length in the block monoid over the listed group. For purposes of aggregating the data, we also provide a
spreadsheet
(in Microsoft Excel format) and a
csv
(comma separated values) file that include all the groups and the numbers of atoms of all lengths. The csv file was produced using the program
read_atomout.c
from the files linked in the table below; the routine is linked here as an example of reading the files for inclusion in analysis programs. The counts files in the following table were created with the program
atoms.c
, which uses as input a group table created by
agt.c
. Note that atoms.c should be compiled and run on a 64-bit architecture if it is intended to be used to explore groups of order above about 78.
Order
Cyclic
Rank 2
Rank 3
Rank 4
Rank 5
Rank 6
1
Z
1
2
Z
2
3
Z
3
4
Z
4
Z
2
×
Z
2
5
Z
5
6
Z
6
7
Z
7
8
Z
8
Z
2
×
Z
4
Z
2
×
Z
2
×
Z
2
9
Z
9
Z
3
×
Z
3
10
Z
10
11
Z
11
12
Z
12
Z
2
×
Z
6
13
Z
13
14
Z
14
15
Z
15
16
Z
16
Z
2
×
Z
8
Z
4
×
Z
4
Z
2
×
Z
2
×
Z
4
Z
2
×
Z
2
×
Z
2
×
Z
2
17
Z
17
18
Z
18
19
Z
19
20
Z
20
Z
2
×
Z
10
21
Z
21
22
Z
22
23
Z
23
24
Z
24
Z
2
×
Z
12
Z
2
×
Z
2
×
Z
6
25
Z
25
Z
5
×
Z
5
26
Z
26
27
Z
27
Z
3
×
Z
9
Z
3
×
Z
3
×
Z
3
28
Z
28
Z
2
×
Z
14
29
Z
29
30
Z
30
31
Z
31
32
Z
32
Z
2
×
Z
16
Z
4
×
Z
8
Z
2
×
Z
2
×
Z
8
Z
2
×
Z
4
×
Z
4
Z
2
×
Z
2
×
Z
2
×
Z
4
Z
2
×
Z
2
×
Z
2
×
Z
2
×
Z
2
33
Z
33
34
Z
34
35
Z
35
36
Z
36
Z
2
×
Z
18
Z
3
×
Z
12
Z
6
×
Z
6
37
Z
37
38
Z
38
39
Z
39
40
Z
40
Z
2
×
Z
20
Z
2
×
Z
2
×
Z
10
41
Z
41
42
Z
42
43
Z
43
44
Z
44
Z
2
×
Z
22
45
Z
45
Z
3
×
Z
15
46
Z
46
47
Z
47
48
Z
48
Z
2
×
Z
24
Z
4
×
Z
12
Z
2
×
Z
2
×
Z
12
Z
2
×
Z
2
×
Z
2
×
Z
6
49
Z
49
Z
7
×
Z
7
50
Z
50
Z
5
×
Z
10
51
Z
51
52
Z
52
Z
2
×
Z
26
53
Z
53
54
Z
54
Z
3
×
Z
18
Z
3
×
Z
3
×
Z
6
55
Z
55
56
Z
56
Z
2
×
Z
28
Z
2
×
Z
2
×
Z
14
57
Z
57
58
Z
58
59
Z
59
60
Z
60
Z
2
×
Z
30
61
Z
61
62
Z
62
63
Z
63
Z
3
×
Z
21
64
Z
64
Z
2
×
Z
32
Z
4
×
Z
16
Z
8
×
Z
8
Z
2
×
Z
2
×
Z
16
Z
2
×
Z
4
×
Z
8
Z
4
×
Z
4
×
Z
4
Z
2
×
Z
2
×
Z
2
×
Z
8
Z
2
×
Z
2
×
Z
4
×
Z
4
Z
2
×
Z
2
×
Z
2
×
Z
2
×
Z
4
Z
2
×
Z
2
×
Z
2
×
Z
2
×
Z
2
×
Z
2
65
Z
65
66
Z
66
67
Z
67
68
Z
68
Z
2
×
Z
34
69
Z
69
70
Z
70
71
Z
71
72
Z
72
Z
2
×
Z
36
Z
3
×
Z
24
Z
6
×
Z
12
Z
2
×
Z
2
×
Z
18
Z
2
×
Z
6
×
Z
6
73
Z
73
74
Z
74
75
Z
75
Z
5
×
Z
15
76
Z
76
Z
2
×
Z
38
77
Z
77
78
Z
78
79
Z
79
80
Z
80
Z
2
×
Z
40
Z
4
×
Z
20
Z
2
×
Z
2
×
Z
20
Z
2
×
Z
2
×
Z
2
×
Z
10
81
Z
81
Z
3
×
Z
27
Z
9
×
Z
9
Z
3
×
Z
3
×
Z
9
Z
3
×
Z
3
×
Z
3
×
Z
3
82
Z
82
83
Z
83
84
Z
84
Z
2
×
Z
42
85
Z
85
86
Z
86
87
Z
87
88
Z
88
Z
2
×
Z
44
Z
2
×
Z
2
×
Z
22
89
Z
89
90
Z
90
Z
3
×
Z
30
91
Z
91
92
Z
92
Z
2
×
Z
46
93
Z
93
94
Z
94
95
Z
95
96
Z
96
Z
2
×
Z
48
Z
4
×
Z
24
Z
2
×
Z
2
×
Z
24
Z
2
×
Z
4
×
Z
12
Z
2
×
Z
2
×
Z
2
×
Z
12
Z
2
×
Z
2
×
Z
2
×
Z
2
×
Z
6
97
Z
97
98
Z
98
Z
7
×
Z
14
99
Z
99
Z
3
×
Z
33
100
Z
100
Z
2
×
Z
50
Z
5
×
Z
20
Z
10
×
Z
10
101
Z
101