A183362 T(n,k)=One quarter the number of nXk 1..4 arrays with no two neighbors of any element equal to each other.

1, 4, 4, 12, 36, 12, 36, 144, 144, 36, 108, 576, 432, 576, 108, 324, 2304, 1296, 1296, 2304, 324, 972, 9216, 3888, 3600, 3888, 9216, 972, 2916, 36864, 11664, 9216, 9216, 11664, 36864, 2916, 8748, 147456, 34992, 24336, 24192, 24336, 34992, 147456, 8748

Offset: 1

Author

R. H. Hardin Jan 04 2011

Keywords

• nonn
• tabl

Comments

Table starts

.....1.......4.....12......36.....108.....324.....972.....2916.....8748

.....4......36....144.....576....2304....9216...36864...147456...589824

....12.....144....432....1296....3888...11664...34992...104976...314928

....36.....576...1296....3600....9216...24336...63504...166464...435600

...108....2304...3888....9216...24192...57600..137088...331776...802944

...324....9216..11664...24336...57600..147456..331776...746496..1679616

...972...36864..34992...63504..137088..331776..829440..1806336..3852288

..2916..147456.104976..166464..331776..746496.1806336..4460544..9437184

..8748..589824.314928..435600..802944.1679616.3852288..9437184.23003136

.26244.2359296.944784.1140624.1937664.3873024.8294400.19501056.47775744

Examples

			Some solutions for 6X5 with a(1,1)=1
..1..1..3..2..2....1..1..3..2..1....1..1..4..2..3....1..1..3..2..4
..4..4..3..1..1....2..2..4..4..3....3..3..4..1..3....4..4..3..1..1
..3..2..2..4..4....4..3..1..1..3....4..2..2..1..4....3..2..2..4..3
..3..1..1..3..2....4..3..2..2..4....4..1..3..3..4....3..1..1..4..3
..2..4..4..3..1....1..1..4..3..1....3..1..4..2..2....2..4..3..2..2
..1..3..2..2..1....2..2..4..3..1....3..2..4..1..3....1..4..3..1..4
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..335

Crossrefs

Column 1 is A003946(n-1)