A217028 - OEIS

%I #4 Sep 24 2012 09:04:52

%S 0,1,1,2,16,2,4,121,121,4,8,1024,3456,1024,8,16,8464,108900,108900,

%T 8464,16,32,70225,3356150,12931216,3356150,70225,32,64,582169,

%U 103754596,1501795009,1501795009,103754596,582169,64,128,4826809,3204762800

%N 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 and no element acquiring more than two neighbors

%C Table starts

%C ...0.........1..............2....................4..........................8

%C ...1........16............121.................1024.......................8464

%C ...2.......121...........3456...............108900....................3356150

%C ...4......1024.........108900.............12931216.................1501795009

%C ...8......8464........3356150...........1501795009...............655816458528

%C ..16.....70225......103754596.........174892912804............287247245656900

%C ..32....582169.....3204762800.......20353081850721.........125713947023634648

%C ..64...4826809....99000846736.....2368756732515625.......55023794225718350400

%C .128..40018276..3058191082836...275676538509042724....24082627794060829296632

%C .256.331786225.94469768837136.32083375146710009409.10540437995119428253155204

%H R. H. Hardin, <a href="/A217028/b217028.txt">Table of n, a(n) for n = 1..180</a>

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

%e ..2..2..3..2....2..1..2..3....1..1..1..2....1..3..2..3....1..2..1..3

%e ..0..2..1..2....2..2..2..0....1..2..2..2....0..3..0..2....2..1..0..0

%e ..1..0..0..3....0..1..0..0....0..0..0..0....0..3..1..3....1..0..1..0

%K nonn,tabl

%O 1,4

%A _R. H. Hardin_ Sep 24 2012