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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.
3

%I #8 Jan 02 2021 14:56:54

%S 1,3,6,14,32,66,134,280,585,1214,2462,4946,9861,19600,38688,76086,

%T 148435,288098,554970,1062628,2016814,3800682,7093209,13127364,

%U 24053454,43657576,78382622,139237375

%N 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.

%o See link in A089473.

%o (Python) # uses alst(), swap() in A089473

%o start, shape = "1-23456789ABCDEF", (4, 4)

%o print(alst(start, shape, maxd=16)) # _Michael S. Branicky_, Jan 02 2021

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

%K fini,more,nonn

%O 0,2

%A _Hugo Pfoertner_, Nov 27 2003

%E a(17)-a(27) from _Michael S. Branicky_, Dec 28 2020