The On-Line Encyclopedia of Integer Sequences (OEIS)

A090164 revision #4

A090164

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.

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

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,2

LINKS

Table of n, a(n) for n=0..26.

MAPLE

See link in A089473.

CROSSREFS

Cf. A087725, A089484, A090165.

Sequence in context: A301178 A279262 A168673 * A261635 A258346 A128640

Adjacent sequences: A090161 A090162 A090163 * A090165 A090166 A090167

KEYWORD

fini,more,nonn

AUTHOR

Hugo Pfoertner, Nov 27 2003

EXTENSIONS

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

STATUS

proposed