Invitation: celebrating 50 years of OEIS, 250000 sequences, and Sloane's 75th, there will be a conference at DIMACS, Rutgers, Oct 9-10 2014.
A090377
Number of configurations that require a minimum of n moves to be reached, starting with the empty square in one of the corners of an infinitely large extension of Sam Loyd's sliding block 15-puzzle.
The first n terms of this sequence coincide with the first n terms of the corresponding sequences for n X n sliding block puzzles (see Cross-references).