A201958 T(n,k)=Number of zero-sum nXk -3..3 arrays with every element unequal to at most two horizontal and vertical neighbors.

1, 7, 7, 37, 231, 37, 231, 1587, 1587, 231, 1451, 17903, 17091, 17903, 1451, 9331, 194633, 303955, 303955, 194633, 9331, 60691, 2232183, 4735345, 9654533, 4735345, 2232183, 60691, 398567, 25952953, 85454789, 300895245, 300895245, 85454789

Offset: 1

Author

R. H. Hardin Dec 06 2011

Keywords

• nonn
• tabl

Comments

Table starts

......1........7.......37.......231......1451........9331......60691....398567

......7......231.....1587.....17903....194633.....2232183...25952953.305979795

.....37.....1587....17091....303955...4735345....85454789.1489376611

....231....17903...303955...9654533.300895245.10356370455

...1451...194633..4735345.300895245

...9331..2232183.85454789

..60691.25952953

.398567

Examples

			Some solutions for n=3 k=3
..0.-3..1....1.-3..3....1..1..0....0..1..1...-2..1..3....2..3..3...-3..1..0
.-3.-3..3...-3.-3.-3...-1.-1.-1....0..1..1...-2..1..3....0..0..0...-3..1..1
..1..1..3....3..3..2....2.-1..0...-3..1.-2...-3..1.-2...-2.-3.-3....0..0..3
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..40

Crossrefs

Column 1 is A025012