A198150 - OEIS

%I #9 Oct 03 2025 07:47:12

%S 2,12,54,240,1170,5330,24689,116890,549479,2578328,12131698,57065922,

%T 268256602,1261383897,5931754425,27891320698,131147135601,

%U 616682910805,2899744304684,13635001788168,64114012351029,301474577118884

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

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

%C Column 3 of A198155

%H R. H. Hardin, <a href="/A198150/b198150.txt">Table of n, a(n) for n = 1..200</a>

%F Empirical: a(n) = 2*a(n-1) +3*a(n-2) +38*a(n-3) +40*a(n-4) +21*a(n-5) -127*a(n-6) -313*a(n-7) -143*a(n-8) +681*a(n-9) +1988*a(n-10) +1587*a(n-11) -1232*a(n-12) -4569*a(n-13) -5344*a(n-14) -992*a(n-15) +3626*a(n-16) +4576*a(n-17) +2900*a(n-18) +162*a(n-19) -844*a(n-20) -954*a(n-21) -250*a(n-22) +190*a(n-23) +34*a(n-24) -a(n-25)

%e Some solutions for n=4

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Oct 21 2011