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A268809 T(n,k)=Number of nXk 0..2 arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two not more than once. 8
3, 9, 9, 24, 34, 24, 60, 104, 104, 60, 144, 290, 332, 290, 144, 336, 772, 1202, 1202, 772, 336, 768, 1972, 4158, 5848, 4158, 1972, 768, 1728, 4914, 14308, 28452, 28452, 14308, 4914, 1728, 3840, 12010, 48460, 135912, 195384, 135912, 48460, 12010, 3840, 8448 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Table starts

....3.....9......24.......60........144.........336...........768

....9....34.....104......290........772........1972..........4914

...24...104.....332.....1202.......4158.......14308.........48460

...60...290....1202.....5848......28452......135912........640926

..144...772....4158....28452.....195384.....1316226.......8734264

..336..1972...14308...135912....1316226....12432856.....115671422

..768..4914...48460...640926....8734264...115671422....1508087180

.1728.12010..162722..2990786...57302798..1062318610...19390335102

.3840.28922..541744.13835892..372342650..9657289546..246666802206

.8448.68836.1791504.63544542.2400532536.87052567448.3110082281974

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..637

FORMULA

Empirical for column k:

k=1: a(n) = 4*a(n-1) -4*a(n-2)

k=2: a(n) = 2*a(n-1) +3*a(n-2) -2*a(n-3) -6*a(n-4) -4*a(n-5) -a(n-6) for n>7

k=3: [order 10] for n>12

k=4: [order 16] for n>19

k=5: [order 26] for n>29

k=6: [order 42] for n>45

k=7: [order 68] for n>71

EXAMPLE

Some solutions for n=4 k=4

..1..2..1..2. .1..0..0..0. .2..2..1..2. .2..1..0..1. .2..2..1..2

..1..2..2..2. .0..0..1..0. .1..2..2..2. .0..0..0..0. .1..2..1..2

..2..2..2..1. .0..0..0..1. .2..1..2..1. .0..1..0..0. .2..2..2..2

..2..2..2..2. .0..0..0..0. .2..2..1..2. .0..0..0..0. .2..2..1..2

CROSSREFS

Column 1 is A084858.

Sequence in context: A207235 A207228 A207015 * A268628 A269052 A268971

Adjacent sequences:  A268806 A268807 A268808 * A268810 A268811 A268812

KEYWORD

nonn,tabl

AUTHOR

R. H. Hardin, Feb 13 2016

STATUS

approved

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Last modified September 24 10:57 EDT 2020. Contains 337317 sequences. (Running on oeis4.)