A207812 Number of 7Xn 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 1 0 and 1 0 1 vertically.

42, 1764, 14406, 212814, 2472540, 31569510, 388134978, 4844843724, 60105117534, 747536620446, 9287588538564, 115441611327546, 1434634623961938, 17830155700946568, 221591726286572670, 2753968042158084066

Offset: 1

Author

R. H. Hardin Feb 20 2012

Keywords

• nonn

Comments

Row 7 of A207808

Examples

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

Links

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

Formula

Empirical: a(n) = 6*a(n-1) +111*a(n-2) -215*a(n-3) -2612*a(n-4) +4413*a(n-5) +22651*a(n-6) -38339*a(n-7) -87492*a(n-8) +141631*a(n-9) +180683*a(n-10) -251999*a(n-11) -220845*a(n-12) +230015*a(n-13) +159866*a(n-14) -110128*a(n-15) -65501*a(n-16) +27211*a(n-17) +14223*a(n-18) -3284*a(n-19) -1500*a(n-20) +176*a(n-21) +69*a(n-22) -3*a(n-23) -a(n-24)