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 2079.
Table of n, a(n) for n=0..10.
Jaap Scherphuis, Puzzle Pages
Cf. A010928, A080560-A080564.
Sequence in context: A049598 A342914 A152135 * A212963 A033196 A172218
Adjacent sequences: A080559 A080560 A080561 * A080563 A080564 A080565
N. J. A. Sloane, Feb 21 2003