No. of clustering arrangements: 1
The clusters are: {{r1,r2,r3}}

No. of clustering arrangements: 3
The clusters are: {{r1,r2},{r3}}, {{r1,r3},{r2}}, {{r2,r3},{r1}}

No. of clustering arrangements: 1
The clusters are: {{r1},{r2},{r3}}

Clustering arrangements with 1 cluster:
No. of clustering arrangements: 1
The clusters are: {{r1,r2,r3,r4}}

No. of clustering arrangements: 7
The clusters are: {{r1,r2,r3},{r4}}, {{r1,r2,r4},{r3}}, {{r1,r3,r4},{r2}}, {{r2,r3,r4},{r1}}, {{r1,r2},{r3,r4}},
{{r1,r3},{r2,r4}}, {{r2,r3},{r1,r4}}

No. of clustering arrangements: 6
The clusters are: {{r1,r2},{r3},{r4}}, {{r1,r3},{r2},{r4}}, {{r1,r4},{r2},{r3}}, {{r2,r3},{r1},{r4}}, {{r2,r4},{r1},{r3}}, {{r3,r4},{r1},{ r2}}

No. of clustering arrangements: 1
The clusters are: {{r1},{r2},{r3},{r4}}