A196953 Number of nX4 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 2,1,3,4,0 for x=0,1,2,3,4.

4, 20, 87, 492, 2687, 14509, 78717, 427700, 2320738, 12593583, 68356288, 370995901, 2013496775, 10928042781, 59310677884, 321900611044, 1747074166413, 9482023129916, 51462457739671, 279305865035645, 1515896714830837

Offset: 1

Author

R. H. Hardin Oct 08 2011

Keywords

• nonn

Comments

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

Column 4 of A196957

Examples

			Some solutions for n=5
..0..0..0..0....0..0..1..1....0..0..1..1....0..0..0..0....0..0..1..1
..0..0..0..0....0..1..0..0....1..0..0..0....1..0..0..0....0..0..0..0
..0..4..0..0....0..1..0..0....1..0..1..1....1..0..4..0....0..4..0..0
..0..0..1..0....0..0..0..1....0..0..0..0....0..0..0..1....0..0..0..0
..0..0..1..0....0..0..0..1....0..0..1..1....0..0..0..1....1..1..0..0
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 2*a(n-1) +10*a(n-2) +37*a(n-3) +54*a(n-4) -39*a(n-6) -10*a(n-7) -37*a(n-8) -49*a(n-9) -18*a(n-10) -9*a(n-11) -16*a(n-12) +6*a(n-13) -a(n-14) +a(n-15) for n>16