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

1,1

Comments

Column 4 of A229380

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) +19880682*a(n-13) +5584682*a(n-14) -21686564*a(n-15) -1854284*a(n-16) +12002158*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

Example

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

Crossrefs

Sequence in context: A341597 A334306 A069140 * A298684 A316458 A184191

Adjacent sequences: A229373 A229374 A229375 * A229377 A229378 A229379

Keyword

nonn

Author

R. H. Hardin Sep 21 2013

Status

approved