A183365 Number of nX3 binary arrays with no element equal to the sum mod 3 of its horizontal and vertical neighbors.

2, 5, 18, 39, 108, 288, 795, 2278, 6438, 18394, 52556, 150565, 431730, 1238954, 3556322, 10210036, 29317763, 84190569, 241782416, 694380738, 1994246166, 5727497628, 16449560195, 47243891395, 135686993036, 389700996218

Offset: 1

Author

R. H. Hardin Jan 04 2011

Keywords

• nonn

Comments

Column 3 of A183368

Examples

			Some solutions for 5X3
..1..0..1....1..1..1....0..1..1....0..0..0....1..1..0....0..1..1....1..1..0
..0..0..0....1..1..1....1..1..1....1..1..1....1..1..0....0..1..1....1..1..0
..1..1..0....0..0..0....1..0..1....1..1..1....1..1..0....0..1..1....0..0..1
..1..1..0....0..0..1....1..1..1....0..0..0....0..1..1....0..1..1....1..0..0
..0..0..1....1..0..0....1..1..0....0..1..0....0..1..1....1..0..0....0..1..0
		

Links

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

Formula

Empirical: a(n)=3*a(n-1)+a(n-3)-4*a(n-4)+4*a(n-5)-22*a(n-6)-12*a(n-7)-21*a(n-8)+22*a(n-9)-13*a(n-10)+115*a(n-11)+79*a(n-12)+116*a(n-13)-45*a(n-14)+172*a(n-15)-75*a(n-16)-54*a(n-17)-181*a(n-18)-85*a(n-19)-61*a(n-20)-11*a(n-21)-158*a(n-22)+80*a(n-23)+157*a(n-24)+215*a(n-25)-78*a(n-26)-211*a(n-27)-196*a(n-28)-51*a(n-29)+44*a(n-30)+81*a(n-31)+64*a(n-32)+13*a(n-33)-13*a(n-34)-12*a(n-35)-7*a(n-36)-a(n-37)+a(n-38)+a(n-39)