A201843 Number of zero-sum n X 4 -1..1 arrays with every element equal to at least one horizontal or vertical neighbor.

3, 97, 2019, 54773, 1566319, 47249907, 1459651671, 45844870481, 1455414376611, 46555250810519, 1497485960091173, 48374845748963503, 1568089004921104931, 50975155483748682379, 1661095734808928183917, 54241996928659097913681

Offset

1,1

Comments

Column 4 of A201847.

Links

R. H. Hardin, Table of n, a(n) for n = 1..25

Example

Some solutions for n=4
..0..1..1..0...-1..1..0..0...-1.-1.-1..1....1.-1.-1..1....0.-1.-1.-1
..0..1..0..0...-1..1.-1.-1....0..1..1..1....1.-1..1..1....0..0..0.-1
.-1..1..0..0...-1.-1..1..1....0..1.-1..1...-1.-1..1..1....1..1..0..0
.-1.-1.-1..0....1..1..0..0...-1.-1.-1..1...-1.-1.-1..1....0..0..1..1

Crossrefs

Cf. A201847.

Sequence in context: A320517 A348491 A243155 * A278202 A246537 A057014

Adjacent sequences: A201840 A201841 A201842 * A201844 A201845 A201846

Keyword

nonn

Author

R. H. Hardin Dec 06 2011

Status

approved