A207930 Number of 4Xn 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 0 0 and 1 1 1 vertically.

10, 100, 240, 576, 1872, 6084, 18096, 53824, 165648, 509796, 1542240, 4665600, 14251680, 43533604, 132223920, 401601600, 1223922960, 3730033476, 11344617648, 34503805504, 105068389776, 319946347044, 973567075392, 2962474361856

Offset: 1

Author

R. H. Hardin Feb 21 2012

Keywords

• nonn

Comments

Row 4 of A207928

Examples

			Some solutions for n=8
..1..0..1..1..1..0..0..1....0..1..1..0..1..1..1..0....0..1..1..0..1..1..0..1
..0..0..1..1..0..1..1..0....1..1..1..0..0..1..1..1....0..1..1..0..0..1..1..0
..1..1..0..0..1..1..1..0....1..0..0..1..1..0..0..1....1..0..0..1..1..0..1..1
..1..0..1..1..1..0..0..1....0..0..1..1..1..1..1..0....0..1..1..0..1..1..0..1
		

Links

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

Formula

Empirical: a(n) = a(n-1) -a(n-2) +8*a(n-3) +34*a(n-4) +14*a(n-5) +42*a(n-6) -42*a(n-8) -14*a(n-9) -34*a(n-10) -8*a(n-11) +a(n-12) -a(n-13) +a(n-14) for n>15