A185825 T(n,k)=1/5 the number of nXk 0..4 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors.

0, 1, 1, 1, 9, 1, 5, 76, 76, 5, 9, 656, 1584, 656, 9, 29, 5680, 49036, 49036, 5680, 29, 65, 49248, 1266624, 4443292, 1266624, 49248, 65, 181, 426928, 35446376, 378212944, 378212944, 35446376, 426928, 181, 441, 3701360, 956312244, 32995092992

Offset: 1

Author

R. H. Hardin Feb 05 2011

Keywords

• nonn
• tabl

Comments

Table starts

....0........1...........1.............5..............9.............29

....1........9..........76...........656...........5680..........49248

....1.......76........1584.........49036........1266624.......35446376

....5......656.......49036.......4443292......378212944....32995092992

....9.....5680.....1266624.....378212944...100480040192.28043363244452

...29....49248....35446376...32995092992.28043363244452

...65...426928...956312244.2852526229300

..181..3701360.26231137608

..441.32089696

.1165

Examples

			Some solutions for 5X4 with a(1,1)=0
..0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0
..1..1..1..0....0..1..1..0....1..1..1..0....1..1..1..0....0..1..1..0
..3..0..3..0....4..2..2..0....2..3..0..0....2..2..2..0....4..1..2..0
..3..0..3..0....4..0..2..1....2..3..0..2....0..0..4..4....4..0..2..4
..3..2..2..2....0..0..2..1....3..3..0..2....4..4..2..2....4..0..2..4
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..60

Crossrefs

Column 1 is A006131(n-2)