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

0,2

Links

Table of n, a(n) for n=0..27.

Prog

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

Crossrefs

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

Sequence in context: A006356 A077998 A209357 * A129954 A238768 A272362

Adjacent sequences: A090162 A090163 A090164 * A090166 A090167 A090168

Keyword

fini,more,nonn

Author

Hugo Pfoertner, Nov 27 2003

Extensions

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

Status

approved