A089474 Number of configurations of the sliding block 8-puzzle that require a minimum of n moves to be reached, starting with the empty square in the center.

1, 4, 8, 8, 16, 32, 60, 72, 136, 200, 376, 512, 964, 1296, 2368, 3084, 5482, 6736, 11132, 12208, 18612, 18444, 24968, 19632, 22289, 13600, 11842, 4340, 2398, 472, 148

Offset: 0

Author

Hugo Pfoertner, Nov 19 2003

Keywords

• fini
• full
• nonn

Examples

			Starting with
123
4-5
678
two of the 148 configurations that require the maximum of 30 moves are
476 ... -86
2-8 and 724
351 ... 351
		

References

• See A087725.

Links

• Hugo Pfoertner, Table of solution lengths of the 8-puzzle

Crossrefs

Cf. A089473, A089483, A089484, A087725, A090031.

Programs

Maple

See link in A089473.

Python

# alst(), moves(), swap() in A089473
print(alst("1234-5678", (3, 3))) # Michael S. Branicky, Dec 30 2020