A201884 Number of zero-sum nX1 -2..2 arrays with every element equal to at least one horizontal or vertical neighbor

0, 1, 1, 5, 1, 23, 25, 97, 155, 553, 893, 2945, 5721, 16499, 34509, 96903, 211929, 571639, 1310827, 3446631, 8106415, 21036009, 50484447, 129556711, 315618625, 804915729, 1980809241, 5032086931, 12478845269, 31624865741, 78861551727

Offset

1,4

Comments

Column 1 of A201888

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Example

Some solutions for n=8
..2...-2....1...-2....0....0....1....1....2....1...-1....0....0...-2...-1....0
..2...-2....1...-2....0....0....1....1....2....1...-1....0....0...-2...-1....0
..0....0....0....2...-2....1....0...-1...-1...-1...-1...-1....0....2...-2....1
..0....0....0....2...-2....1....0...-1...-1...-1...-1...-1....0....2...-2....1
.-2....1...-2...-2....1...-2....0...-1....1....2....2...-1....1....0....1....1
.-2....1...-2...-2....1...-2....0...-1....1....2....2....1....1....0....1....1
..0....1....1....2....1....1...-1....1...-2...-2....0....1...-1....0....2...-2
..0....1....1....2....1....1...-1....1...-2...-2....0....1...-1....0....2...-2

Crossrefs

Sequence in context: A167572 A147476 A146675 * A294138 A207824 A179900

Adjacent sequences: A201881 A201882 A201883 * A201885 A201886 A201887

Keyword

nonn

Author

R. H. Hardin Dec 06 2011

Status

approved