A207393 Number of 4Xn 0..1 arrays avoiding 0 0 1 and 0 1 0 horizontally and 0 0 1 and 1 1 0 vertically.

8, 64, 200, 643, 2356, 7561, 23071, 72410, 223804, 678174, 2060069, 6253794, 18886989, 56994221, 172026022, 518680170, 1563104966, 4710798095, 14194683842, 42764679095, 128836561789, 388135277342, 1169254115920, 3522329560926

Offset: 1

Author

R. H. Hardin Feb 17 2012

Keywords

• nonn

Comments

Row 4 of A207391

Examples

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

Links

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

Formula

Empirical: a(n) = 5*a(n-1) -8*a(n-2) +19*a(n-3) -54*a(n-4) +51*a(n-5) -64*a(n-6) +169*a(n-7) -78*a(n-8) +62*a(n-9) -265*a(n-10) +27*a(n-11) -41*a(n-12) +277*a(n-13) +16*a(n-14) +40*a(n-15) -162*a(n-16) -31*a(n-17) -10*a(n-18) +41*a(n-19) +13*a(n-20) -6*a(n-22)