A079761 Number of positions that are exactly n moves from the starting position in the 2 X 2 X 2 Rubik cube puzzle counting a half-turn as a single move.

1, 9, 54, 321, 1847, 9992, 50136, 227536, 870072, 1887748, 623800, 2644

Offset: 0

Author

N. J. A. Sloane, Feb 20 2003

Keywords

• nonn
• fini
• full

Comments

This is the number of positions that can be reached in n moves from the start, but which cannot be reached in fewer than n moves.

A puzzle in the Rubik cube family. The total number of distinct positions is 3674160. A half-turn is considered to be one move.

References

• D. R. Hofstadter, Metamagical Themas, Basic Books, NY, 1985, p. 359.

Links

• Mark Longridge, God's Algorithm Calculations for Rubik's Cube...
• Jaap Scherphuis, Puzzle Pages

Crossrefs

Cf. A079762, A152169.