A197396 - OEIS

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

%S 1,9,17,81,257,1003,3417,12673,46165,168569,614795,2245461,8191537,

%T 29913649,109228305,398768515,1455927145,5315748449,19407950069,

%U 70859924513,258716449075,944591935629,3448776039137,12591745130321

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

%C Every 0 is next to 0 3's, every 1 is next to 1 3'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 A197401

%H R. H. Hardin, <a href="/A197396/b197396.txt">Table of n, a(n) for n = 1..200</a>

%F Empirical: a(n) = a(n-1) +2*a(n-2) +8*a(n-3) +50*a(n-4) +65*a(n-5) +125*a(n-6) -4*a(n-7) -330*a(n-8) -596*a(n-9) -2336*a(n-10) -1872*a(n-11) +712*a(n-12) +520*a(n-13) +4176*a(n-14) +4400*a(n-15) -1728*a(n-16) -384*a(n-17)

%e Some solutions for n=4

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

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

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

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

%K nonn

%O 1,2

%A _R. H. Hardin_ Oct 14 2011