A207023 Number of nX7 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 0 1 and 1 0 1 vertically.

25, 625, 3025, 9450, 23400, 49925, 95900, 170300, 284475, 452425, 691075, 1020550, 1464450, 2050125, 2808950, 3776600, 4993325, 6504225, 8359525, 10614850, 13331500, 16576725, 20424000, 24953300, 30251375, 36412025, 43536375, 51733150

Offset: 1

Author

R. H. Hardin Feb 14 2012

Keywords

• nonn

Comments

Column 7 of A207024

Examples

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

Links

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

Formula

Empirical: a(n) = (55/24)*n^5 + (75/4)*n^4 + (275/8)*n^3 + (75/4)*n^2 - (295/6)*n.

Empirical G.f.: 25*x*(1+19*x-14*x^2+7*x^3-2*x^4)/(1-x)^6. [Colin Barker, May 22 2012]