The Group C1

The Group C1 is the whole cube group which contains 43,252,003,274,489,856,000 elements. Dan Hoey showed in 1994 that this group contains 901,083,404,981,813,616 elements up to M-symmetry. Mike Godfrey and I showed in 2005 that there are 450,541,810,590,509,978 elements up to M-symmetry and antisymmetry.

We have the following table (see sequence A080601 in the On-Line Encyclopedia of Integer Sequences) for the distances in this subgroup:

Distance
Number
Distance
Number
0f
1
11f
3,063,288,809,012
1f
18
12f
40,374,425,656,248
2f
243
13f
531,653,418,284,628
3f
3,240
14f
6,989,320,578,825,358
4f
43,239
15f
91,365,146,187,124,313
5f
574,908
16f
unknown
6f
7,618,438
17f
unknown
7f
100,803,036
18f
unknown
8f
1,332,343,288
19f
unknown
9f
17,596,479,795
20f
unknown
10f
232,248,063,316
21f
0

Because we have the tables for all other symmetry groups except C1 which exactly have a given symmetry, we can compute the table for the number of cubes wich are symmetric:

Distance
Number
Distance
Number
0f
1
11f
9,732,164
1f
18
12f
35,024,904
2f
51
13f
122,054,340
3f
312
14f
436,197,214
4f
1,335
15f
1,763,452,505
5f
4,380
16f
8,035,307,127
6f
17,782
17f
37,542,012,922
7f
70,188
18f
95,387,902,305
8f
229,336
19f
21,267,102,443
9f
851,139
20f
1,091,994
10f
2,989,204
21f
0

This are altogether 164,604,041,664 cubes. By subtracting the second table from the first we can compute the number of cubes which exactly have C1-symmetry (and hence are unsymmetric):

Distance
Number
Distance
Number
0f
0
11f
3,063,279,076,848
1f
0
12f
40,374,390,631,344
2f
192
13f
531,653,296,230,288
3f
2,928
14f
6,989,320,142,628,144
4f
41,904
15f
91,365,144,423,671,808
5f
570,528
16f
unknown
6f
7,600,656
17f
unknown
7f
100,732,848
18f
unknown
8f
13,32,113,952
19f
unknown
9f
17,595,628,656
20f
unknown
10f
232,245,074,112
21f
0

If we want to know the number of cubes which exactly have C1-symmetry mod M, we have to divide all numbers in the last table by 48.

It is interesting to notice that the the probability to get a symmetric cube by random is 164,604,041,664 / 43,252,003,274,489,856,000 which is only about 3.81*10-9.

There are myriads of nice unsymmetric cubes. Some examples are given below.

Name
shortest maneuver with exactly this symmetry
Generator
U R (2f*)
Name
Generator
L2 R F2 R' U' L' U B F2 L2 D' L D' B' (14f*)
Name
Generator
L U B2 L2 D2 B U B' D' R' B' F' U2 B2 U R (16f*)
Name
Generator
R F U F2 U2 R' B' F2 D' L' D2 L2 B D2 (14f*)
Name
Generator
D R D L B D2 B' F D' U F2 U' R' F' L' F' (16f*)
Name
Generator
L2 D2 U2 L' U2 L' R2 D2 U2 R' U2 R' (12f*)

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© 2017  Herbert Kociemba