A229376 Number of nX4 0..2 arrays avoiding 11 horizontally, 22 vertically and 00 diagonally or antidiagonally.

60, 518, 6730, 78690, 956866, 11441370, 138118032, 1657198220, 19969628086, 239888727922, 2888372417962, 34717775838484, 417835837510270, 5023955278338394, 60449751205860716, 726964181424486002

Offset: 1

Author

R. H. Hardin Sep 21 2013

Keywords

• nonn

Comments

Column 4 of A229380

Examples

			Some solutions for n=4
..1..0..0..1....1..2..2..1....2..2..2..1....2..0..1..2....0..0..1..2
..2..1..2..2....0..0..1..0....1..0..0..1....1..2..1..0....2..2..2..0
..0..1..0..1....1..2..1..0....2..2..2..1....1..0..1..0....1..0..1..0
..2..1..2..2....0..0..2..0....0..0..1..2....1..0..2..1....1..0..2..2
		

Links

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

Formula

Empirical: a(n) = 6*a(n-1) +150*a(n-2) -614*a(n-3) -6021*a(n-4) +20473*a(n-5) +101559*a(n-6) -313078*a(n-7) -812145*a(n-8) +2419449*a(n-9) +3153273*a(n-10) -9572428*a(n-11) -6094709*a(n-12) [phone]*a(n-13) +5584682*a(n-14) -21686564*a(n-15) -1854284*a(n-16) [phone]*a(n-17) -190196*a(n-18) -3154524*a(n-19) +224356*a(n-20) +344336*a(n-21) -35568*a(n-22) -12480*a(n-23) +1536*a(n-24) for n>25