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A269109
T(n,k)=Number of nXk 0..3 arrays with some element plus some horizontally or vertically adjacent neighbor totalling three no more than once.
8
4, 16, 16, 60, 180, 60, 216, 1740, 1740, 216, 756, 15540, 40908, 15540, 756, 2592, 132300, 872460, 872460, 132300, 2592, 8748, 1090740, 17593092, 43964700, 17593092, 1090740, 8748, 29160, 8787660, 342055548, 2085484068, 2085484068
OFFSET
1,1
COMMENTS
Table starts
......4.........16.............60................216....................756
.....16........180...........1740..............15540.................132300
.....60.......1740..........40908.............872460...............17593092
....216......15540.........872460...........43964700.............2085484068
....756.....132300.......17593092.........2085484068...........232068730044
...2592....1090740......342055548........95166487524.........24808345933548
...8748....8787660.....6482020140......4227147007836.......2579398703502996
..29160...69580980...120520189980....184069947098892.....262780733311913580
..96228..543538380..2208175854948...7894012975085748...26357371124964908460
.314928.4200069300.39988864047276.334480929126425748.2611360040338484328156
LINKS
FORMULA
Empirical for column k:
k=1: a(n) = 6*a(n-1) -9*a(n-2)
k=2: a(n) = 14*a(n-1) -49*a(n-2) for n>3
k=3: a(n) = 36*a(n-1) -378*a(n-2) +972*a(n-3) -729*a(n-4) for n>5
k=4: [order 6] for n>7
k=5: [order 14] for n>15
k=6: [order 26] for n>27
k=7: [order 64] for n>65
EXAMPLE
Some solutions for n=3 k=4
..0..0..1..2. .0..2..2..0. .0..1..1..1. .0..2..3..1. .2..0..1..0
..0..2..3..3. .0..2..0..1. .0..0..3..1. .0..0..1..3. .0..0..1..1
..1..3..1..3. .1..0..0..2. .0..2..2..3. .0..0..0..2. .2..2..2..3
CROSSREFS
Column 1 is A120926(n+1).
Sequence in context: A207535 A269194 A269143 * A269201 A269289 A267933
KEYWORD
nonn,tabl
AUTHOR
R. H. Hardin, Feb 19 2016
STATUS
approved