A268628 T(n,k)=Number of nXk 0..2 arrays with some element plus some horizontally or vertically adjacent neighbor totalling two no more than once.

3, 9, 9, 24, 42, 24, 60, 174, 174, 60, 144, 666, 1086, 666, 144, 336, 2430, 6300, 6300, 2430, 336, 768, 8586, 34890, 55452, 34890, 8586, 768, 1728, 29646, 187224, 467190, 467190, 187224, 29646, 1728, 3840, 100602, 982086, 3819654, 6000978, 3819654

Offset: 1

Author

R. H. Hardin, Feb 09 2016

Keywords

• nonn
• tabl

Comments

Table starts

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

....9......42.......174.........666..........2430............8586

...24.....174......1086........6300.........34890..........187224

...60.....666......6300.......55452........467190.........3819654

..144....2430.....34890......467190.......6000978........74914554

..336....8586....187224.....3819654......74914554......1430057208

..768...29646....982086....30553014.....915847266.....26758514760

.1728..100602...5063964...240364746...11018667294....493042858032

.3840..336798..25764066..1866503592..130903914954...8974328440044

.8448.1115370.129678528.14342680944.1539375100362.161737670836314

Examples

			Some solutions for n=4 k=4
..2..1..0..0. .1..2..1..0. .0..0..0..0. .1..2..2..2. .0..0..0..1
..1..0..0..0. .0..1..0..0. .0..0..0..0. .2..1..2..2. .0..0..1..0
..2..0..1..0. .1..0..0..0. .1..0..0..0. .1..2..2..2. .0..0..0..1
..2..1..0..1. .0..0..1..1. .2..1..1..0. .0..2..2..2. .0..1..1..2
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..420

Crossrefs

Column 1 is A084858.

Formula

Empirical for column k:

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

k=2: a(n) = 6*a(n-1) -9*a(n-2) for n>3

k=3: a(n) = 10*a(n-1) -29*a(n-2) +20*a(n-3) -4*a(n-4)

k=4: [order 6] for n>7

k=5: [order 10]

k=6: [order 14] for n>15

k=7: [order 26]