login
A090166
Number of configurations of the 4 X 3 variant of Sam Loyd's sliding block 15-puzzle that require a minimum of n moves to be reached, starting with the empty square in one of the corners.
5
1, 2, 4, 9, 20, 37, 63, 122, 232, 431, 781, 1392, 2494, 4442, 7854, 13899, 24215, 41802, 71167, 119888, 198363, 323206, 515778, 811000, 1248011, 1885279, 2782396, 4009722, 5621354, 7647872, 10065800, 12760413, 15570786, 18171606, 20299876, 21587248, 21841159, 20906905, 18899357, 16058335, 12772603, 9515217, 6583181, 4242753, 2503873, 1350268, 643245, 270303, 92311, 27116, 5390, 1115, 86, 18
OFFSET
0,2
COMMENTS
Data from Karlemo and Östergård.
LINKS
Filip R. W. Karlemo and Patric R. J. Östergård, On Sliding Block Puzzles, J. Combin. Math. Combin. Comp. 34 (2000), 97-107.
Takaken, 11-Puzzle Page.
PROG
(Python) # alst(), moves(), swap() in A089473
alst("-123456789AB", (4, 3), v=True) # Michael S. Branicky, Dec 31 2020
CROSSREFS
Cf. A087725. Index of last sequence term: A090033. Other nonsquare sliding block puzzles: A090034, A090035, A090036, A090167.
Sequence in context: A353734 A053024 A240047 * A101338 A018102 A018103
KEYWORD
fini,full,nonn
AUTHOR
Hugo Pfoertner, Nov 27 2003, Jul 07 2007
STATUS
approved