The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A090164

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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 4 central squares.
(history; published version)

#8 by N. J. A. Sloane at Sat Jan 02 14:57:15 EST 2021

STATUS

proposed

approved

#7 by Michael S. Branicky at Sat Jan 02 13:49:51 EST 2021

STATUS

editing

proposed

#6 by Michael S. Branicky at Sat Jan 02 13:49:30 EST 2021

PROG

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

start, shape = "12345-6789ABCDEF", (4, 4)

print(alst(start, shape, maxd=15)) # Michael S. Branicky, Jan 02 2021

STATUS

approved

editing

#5 by N. J. A. Sloane at Mon Dec 28 17:52:02 EST 2020

STATUS

proposed

approved

#4 by Michael S. Branicky at Mon Dec 28 14:20:09 EST 2020

STATUS

editing

proposed

#3 by Michael S. Branicky at Mon Dec 28 14:15:29 EST 2020

DATA

1, 4, 10, 20, 38, 80, 174, 372, 762, 1540, 3072, 6196, 12356, 24516, 48179, 94356, 183432, 355330, 682250, 1301874, 2460591, 4617322, 8580175, 15815664, 28854386, 52154316, 93214030

EXTENSIONS

a(16)-a(26) from Michael S. Branicky, Dec 28 2020

STATUS

approved

editing

#2 by Russ Cox at Sat Mar 31 10:29:03 EDT 2012

AUTHOR

_Hugo Pfoertner (hugo(AT)pfoertner.org), _, Nov 27 2003

Discussion

Sat Mar 31

10:29

OEIS Server: https://oeis.org/edit/global/581

#1 by N. J. A. Sloane at Thu Feb 19 03:00:00 EST 2004

NAME

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 4 central squares.

DATA

1, 4, 10, 20, 38, 80, 174, 372, 762, 1540, 3072, 6196, 12356, 24516, 48179, 94356

OFFSET

0,2

MAPLE

See link in A089473.

CROSSREFS

Cf. A087725, A089484, A090165.

KEYWORD

fini,more,nonn

AUTHOR

Hugo Pfoertner (hugo(AT)pfoertner.org), Nov 27 2003

STATUS

approved