A090165 Number of configurations of Sam Loyd's sliding block 15-puzzle that require a minimum of n moves to be reached, starting with the empty square at one of the 8 non-corner boundary squares.

1, 3, 6, 14, 32, 66, 134, 280, 585, 1214, 2462, 4946, 9861, 19600, 38688, 76086, 148435, 288098, 554970, 1062628, 2016814, 3800682, 7093209, 13127364, 24053454, 43657576, 78382622, 139237375

Offset: 0

Author

Hugo Pfoertner, Nov 27 2003

Keywords

• fini
• more
• nonn

Crossrefs

Cf. A087725, A089473, A089484, A090164, A090378.

Programs

Python

# uses alst(), swap() in A089473
start, shape = "1-23456789ABCDEF", (4, 4)
print(alst(start, shape, maxd=16)) # Michael S. Branicky, Jan 02 2021

Extensions

a(17)-a(27) from Michael S. Branicky, Dec 28 2020