A197426 - OEIS

%I #5 Mar 31 2012 12:36:29

%S 4,20,68,448,2152,10684,55567,280544,1425111,7280350,37165198,

%T 189316196,965915209,4926863205,25123365839,128156345456,653685106884,

%U 3334114760247,17006120383127,86741818975198,442435364449588

%N Number of nX3 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 4,0,1,1,1 for x=0,1,2,3,4

%C Every 0 is next to 0 4's, every 1 is next to 1 0's, every 2 is next to 2 1's, every 3 is next to 3 1's, every 4 is next to 4 1's

%C Column 3 of A197431

%H R. H. Hardin, <a href="/A197426/b197426.txt">Table of n, a(n) for n = 1..200</a>

%F Empirical: a(n) = 4*a(n-1) +8*a(n-2) +2*a(n-3) -55*a(n-4) +13*a(n-5) -31*a(n-6) -1395*a(n-7) -7003*a(n-8) +190*a(n-9) +23621*a(n-10) +39494*a(n-11) +136485*a(n-12) +189052*a(n-13) +97313*a(n-14) -54613*a(n-15) -41550*a(n-16) -8281*a(n-17) -61318*a(n-18) -115671*a(n-19) -54446*a(n-20) +31678*a(n-21) -10581*a(n-22) +13927*a(n-23) -1446*a(n-24) +8349*a(n-25) -8652*a(n-26) +4905*a(n-27) -966*a(n-28) +1251*a(n-29) -457*a(n-30) -57*a(n-31) +6*a(n-32) +a(n-34)

%e Some solutions for n=4

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Oct 14 2011