A197445 Number of nX3 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 2,1,1,0,0 for x=0,1,2,3,4.

3, 12, 81, 474, 2678, 15410, 88767, 510482, 2936714, 16895217, 97197637, 559175541, 3216923150, 18506887013, 106469709385, 612517802024, 3523801014059, 20272347435052, 116626354899557, 670948774602366, 3859953085161367

Offset: 1

Author

R. H. Hardin Oct 15 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 1's, every 3 is next to 3 0's, every 4 is next to 4 0's

Column 3 of A197450

Examples

			Some solutions for n=4
..1..1..0....1..0..0....0..1..1....0..3..0....0..1..1....0..1..1....1..1..0
..0..0..0....1..3..0....3..0..0....0..0..0....0..3..0....0..0..0....0..0..0
..0..3..1....0..0..1....0..0..0....0..0..3....0..0..0....3..0..1....0..0..0
..0..0..1....0..0..1....0..1..1....0..0..0....0..0..0....0..0..1....0..3..0
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..200

Formula

Empirical: a(n) = 2*a(n-1) +12*a(n-2) +45*a(n-3) +61*a(n-4) +20*a(n-5) -129*a(n-6) -324*a(n-7) -344*a(n-8) -166*a(n-9) +61*a(n-10) +268*a(n-11) +360*a(n-12) +307*a(n-13) +240*a(n-14) +92*a(n-15) -97*a(n-16) -142*a(n-17) -120*a(n-18) -92*a(n-19) -32*a(n-20) -4*a(n-22) for n>25