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A304551 T(n,k)=Number of nXk 0..1 arrays with every element unequal to 0, 2, 3, 4 or 6 king-move adjacent elements, with upper left element zero. 7
1, 1, 1, 1, 4, 1, 1, 8, 8, 1, 1, 24, 13, 24, 1, 1, 82, 60, 60, 82, 1, 1, 272, 217, 418, 217, 272, 1, 1, 908, 749, 2186, 2186, 749, 908, 1, 1, 3076, 2822, 12281, 16782, 12281, 2822, 3076, 1, 1, 10444, 10516, 72713, 127607, 127607, 72713, 10516, 10444, 1, 1, 35480, 38934 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,5

COMMENTS

Table starts

.1.....1.....1.......1........1..........1...........1.............1

.1.....4.....8......24.......82........272.........908..........3076

.1.....8....13......60......217........749........2822.........10516

.1....24....60.....418.....2186......12281.......72713........423041

.1....82...217....2186....16782.....127607.....1061345.......8678318

.1...272...749...12281...127607....1368963....16063367.....183955750

.1...908..2822...72713..1061345...16063367...274090332....4486557450

.1..3076.10516..423041..8678318..183955750..4486557450..104360036860

.1.10444.38934.2465234.70215574.2091952988.72881502770.2402493576235

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..180

FORMULA

Empirical for column k:

k=1: a(n) = a(n-1)

k=2: a(n) = 4*a(n-1) -2*a(n-2) +2*a(n-3) -6*a(n-4) -4*a(n-5) for n>6

k=3: [order 20] for n>21

k=4: [order 70] for n>72

EXAMPLE

Some solutions for n=5 k=4

..0..1..1..1. .0..0..0..0. .0..1..0..1. .0..1..0..1. .0..1..1..1

..1..0..0..0. .1..1..1..1. .0..1..0..0. .0..1..1..0. .1..0..0..0

..0..0..1..0. .1..1..1..1. .1..1..1..1. .1..1..1..0. .1..1..1..1

..0..1..1..0. .1..1..1..1. .1..0..1..1. .0..1..1..1. .0..1..1..1

..0..1..1..0. .0..0..0..0. .1..0..0..0. .0..1..0..0. .0..1..1..1

CROSSREFS

Column 2 is A303882.

Sequence in context: A305281 A304894 A316576 * A316376 A306136 A317271

Adjacent sequences:  A304548 A304549 A304550 * A304552 A304553 A304554

KEYWORD

nonn,tabl

AUTHOR

R. H. Hardin, May 14 2018

STATUS

approved

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Last modified September 21 00:17 EDT 2019. Contains 327252 sequences. (Running on oeis4.)