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

1,2

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

Links

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

Example

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

Crossrefs

Column 1 is A025012

Sequence in context: A372230 A154702 A112685 * A351477 A153721 A286985

Adjacent sequences: A201955 A201956 A201957 * A201959 A201960 A201961

Keyword

nonn,tabl

Author

R. H. Hardin Dec 06 2011

Status

approved