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A079875
Number of positions that are exactly n moves from the starting position in the Lights Out 2000 puzzle.
0
1, 25, 325, 2900, 19850, 110630, 520948, 2125078, 7644164, 24561916, 71147752, 186876765, 446015084, 964537892, 1872111656, 3203446007, 4709112417, 5767439109, 5710406148, 4433675458, 2590026921, 1073252214, 279734731, 36143633, 2147985
OFFSET
0,2
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 31381059609.
PROG
(Python) # alst(), moves() in A079873
shape, states = (5, 5), 3 # 5x5 with off-red-green states
start = tuple([0 for i in range(shape[0]*shape[1])])
print(alst(start, shape, states, v=True)) # Michael S. Branicky, Jan 25 2021
CROSSREFS
Sequence in context: A124980 A188355 A243089 * A162702 A010977 A022589
KEYWORD
nonn,fini,full
AUTHOR
N. J. A. Sloane, Feb 21 2003
STATUS
approved