A208094 Number of n X 4 nonnegative integer arrays with new values 0 upwards introduced in row major order and no element equal to any horizontal, diagonal or antidiagonal neighbor (colorings ignoring permutations of colors).

1, 5, 377, 169064, 235862938, 746823293346, 4493602584256529, 45881957995776221396, 734971289403287420883126, 17434398033181126785548889533, 585880828202059360820577364423099, 26929433656271781956071918468836389588, 1645382407173932261418519657416983542506695

Offset

0,2

Links

Andrew Howroyd, Table of n, a(n) for n = 0..100

Example

Some solutions for n=4
..0..1..0..1....0..1..0..1....0..1..0..1....0..1..0..1....0..1..0..1
..0..1..0..2....0..1..0..1....0..1..2..1....0..1..0..1....0..1..0..2
..2..1..0..1....2..1..0..2....0..1..0..1....0..2..0..1....2..1..0..1
..0..1..2..1....0..1..0..1....0..1..0..1....0..1..0..1....0..1..0..2

Crossrefs

Column 4 of A208096.

Sequence in context: A072172 A278364 A214008 * A273397 A261433 A206386

Adjacent sequences: A208091 A208092 A208093 * A208095 A208096 A208097

Keyword

nonn

Author

R. H. Hardin, Feb 23 2012

Extensions

a(0)=1 prepended and terms a(8) and beyond from Andrew Howroyd, May 17 2020

Status

approved