A216991 - OEIS

A216991

T(n,k)=Number of city-block distance 1, pressure limit 2 movements in an nXk array with each element moving exactly one horizontally or vertically, no element acquiring more than two neighbors, and without 2-loops.

0, 0, 0, 0, 2, 0, 0, 14, 14, 0, 0, 80, 264, 80, 0, 0, 436, 4794, 4794, 436, 0, 0, 2346, 83304, 280900, 83304, 2346, 0, 0, 12578, 1435808, 15836932, 15836932, 1435808, 12578, 0, 0, 67368, 24673352, 886416182, 2891592224, 886416182, 24673352, 67368, 0, 0, 360720

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

OFFSET

1,5

COMMENTS

Table starts

.0........0..............0....................0..........................0

.0........2.............14...................80........................436

.0.......14............264.................4794......................83304

.0.......80...........4794...............280900...................15836932

.0......436..........83304.............15836932.................2891592224

.0.....2346........1435808............886416182...............524266454832

.0....12578.......24673352..........49491906456.............94821314531592

.0....67368......423651134........2761454361344..........17138656649477498

.0...360720.....7272419728......154047246448662........3097157052139827164

.0..1931306...124829530972.....8592994055896310......559661504116914345352

.0.10340030..2142624332680...479322218408145970...101130124206092104688984

.0.55359176.36776621687102.26736736612809407136.18273998071786696959934276

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..241

EXAMPLE

Some solutions for n=3 k=4 (movement: 0=n 1=e 2=s 3=w)

..1..1..2..3....1..1..1..2....2..3..3..3....2..2..2..2....1..2..1..2

..0..0..1..0....0..1..2..2....2..0..1..0....1..2..2..3....2..3..0..3

..1..1..1..0....0..3..3..3....1..1..1..0....0..3..3..3....1..0..3..0

CROSSREFS

Sequence in context: A231049 A231080 A231246 * A191418 A347093 A347094

Adjacent sequences: A216988 A216989 A216990 * A216992 A216993 A216994

KEYWORD

nonn,tabl

AUTHOR

R. H. Hardin, Sep 21 2012

STATUS

approved