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 2880. Here we count half-turn moves.
Table of n, a(n) for n=0..7.
Jaap Scherphuis, Puzzle Pages
Sequence in context: A327387 A282920 A023008 * A169796 A027472 A022637
Adjacent sequences: A079814 A079815 A079816 * A079818 A079819 A079820
N. J. A. Sloane, Feb 20 2003