A317739 Number of nX6 0..1 arrays with every element unequal to 2 or 3 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

0, 9, 4, 23, 38, 22, 36, 140, 146, 218, 736, 1072, 1890, 4505, 8860, 16665, 36236, 77955, 157132, 339776, 741215, 1574853, 3425156, 7498971, 16329476, 35728895, 78504972, 172477510, 378971254, 834963467, 1839342289, 4053198576, 8939535791

Offset

1,2

Comments

Column 6 of A317741.

Links

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

Formula

Empirical: a(n) = 4*a(n-2) +13*a(n-3) -2*a(n-4) -38*a(n-5) -72*a(n-6) +24*a(n-7) +141*a(n-8) +183*a(n-9) -123*a(n-10) -228*a(n-11) -227*a(n-12) +266*a(n-13) -162*a(n-14) +273*a(n-15) -65*a(n-16) +2154*a(n-17) -411*a(n-18) +1075*a(n-19) -5504*a(n-20) +1745*a(n-21) -7708*a(n-22) +5966*a(n-23) -10880*a(n-24) +15631*a(n-25) -7395*a(n-26) +25649*a(n-27) -17569*a(n-28) +18793*a(n-29) -29769*a(n-30) +18327*a(n-31) -32563*a(n-32) +20822*a(n-33) -20922*a(n-34) +34936*a(n-35) -10939*a(n-36) +20583*a(n-37) -25081*a(n-38) +6260*a(n-39) -15245*a(n-40) +12332*a(n-41) -4808*a(n-42) +7884*a(n-43) -4354*a(n-44) +3120*a(n-45) -2603*a(n-46) +1249*a(n-47) -1135*a(n-48) +491*a(n-49) -281*a(n-50) +187*a(n-51) -45*a(n-52) +32*a(n-53) -10*a(n-54) +a(n-55) -a(n-56) for n>63

Example

Some solutions for n=5
..0..1..1..0..1..0. .0..1..0..0..1..1. .0..1..1..1..0..1. .0..1..0..0..1..0
..1..0..0..1..1..0. .1..1..1..0..0..0. .1..0..0..0..0..0. .1..1..1..1..1..1
..0..0..1..1..0..1. .0..1..1..0..1..1. .0..0..1..1..1..0. .0..1..1..0..0..0
..1..1..1..0..0..1. .0..1..0..1..1..0. .1..1..1..1..1..1. .0..0..0..0..0..1
..0..0..1..0..1..0. .1..0..0..1..0..1. .0..0..0..0..1..0. .1..0..1..1..1..0

Crossrefs

Cf. A317741.

Sequence in context: A075066 A061363 A100077 * A174679 A168077 A173536

Adjacent sequences: A317736 A317737 A317738 * A317740 A317741 A317742

Keyword

nonn

Author

R. H. Hardin, Aug 05 2018

Status

approved