A207309 Number of 6Xn 0..1 arrays avoiding 0 0 0 and 1 0 1 horizontally and 0 0 1 and 1 1 0 vertically.

12, 144, 556, 2239, 7093, 23091, 79802, 271023, 906448, 3057442, 10340359, 34870751, 117557963, 396686326, 1338456663, 4514922232, 15230949488, 51384415639, 173349069871, 584798251431, 1972858125612, 6655586739783

Offset: 1

Author

R. H. Hardin Feb 16 2012

Keywords

• nonn

Comments

Row 6 of A207305

Examples

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

Links

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

Formula

Empirical: a(n) = a(n-1) +3*a(n-2) +13*a(n-3) +18*a(n-4) -2*a(n-5) -30*a(n-6) -59*a(n-7) -25*a(n-8) +16*a(n-9) +68*a(n-10) +44*a(n-11) +3*a(n-12) -42*a(n-13) -23*a(n-14) -3*a(n-15) +17*a(n-16) +a(n-17) -2*a(n-18) -2*a(n-19) +3*a(n-20) -a(n-21) for n>22