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 82. Here positions differing by rotations or reflections are considered the same.
Table of n, a(n) for n=0..12.
Jaap Scherphuis, Puzzle Pages
Cf. A010928, A080560-A080564.
Sequence in context: A263652 A285679 A093661 * A266663 A007557 A034746
Adjacent sequences: A080558 A080559 A080560 * A080562 A080563 A080564
N. J. A. Sloane, Feb 21 2003