%I #24 Aug 03 2021 12:43:43

%S 1,2,4,9,21,42,89,164,349,644,1349,2473,5109,9110,18489,32321,64962,

%T 112445,223153,378761,740095,1231589,2364342,3847629,7246578,11506172,

%U 21233764,32854049,59293970,89146163,157015152,228894783,392648931,553489877,922382155

%N Number of configurations of the 5 X 3 variant of the sliding block 15-puzzle that require a minimum of n moves to be reached, starting with the empty square in one of the corners.

%C This sequence was originally computed by Richard Korf, but the full sequence was not included in his paper. It was later re-computed by _Tomas Rokicki_.

%H Ben Whitmore, <a href="/A346737/b346737.txt">Table of n, a(n) for n = 0..84</a>

%H Richard Korf, <a href="https://www.cs.helsinki.fi/u/bmmalone/heuristic-search-fall-2013/Korf2008.pdf">Linear-time Disk-Based Implicit Graph Search</a>, Journal of the ACM 55 (2008), No. 6.

%H Tomas Rokicki, <a href="http://forum.cubeman.org/?q=node/view/238">Twenty-Four puzzle, some observations</a>, 2011.

%e Starting from the solved configuration

%e 1 2 3 4 5

%e 6 7 8 9 10

%e 11 12 13 14

%e the unique configuration requiring 84 moves is

%e 5 4 3 2 1

%e 10 9 8 7 6

%e 14 13 12 11

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

%o print(alst("-123456789abcde", (5, 3), v=True)) # _Michael S. Branicky_, Jul 31 2021

%Y Cf. A090033, A090034, A090035, A090036, A090167, A346736, A090166, A089473, A089484.

%K nonn,fini,full

%O 0,2

%A _Ben Whitmore_, Jul 31 2021