A318337 Number of n X n 0..1 arrays with every element unequal to 0, 1, 2 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

1, 6, 20, 67, 393, 4133, 86487, 3590263, 285034170, 43174729552, 12383193287684, 6712873423988949, 6871475875643572553, 13272675681120501977922, 48367944991570243925176462, 332490278773637201581189154380

Offset

1,2

Comments

Diagonal of A318343.

Links

R. H. Hardin, Table of n, a(n) for n = 1..17

Example

Some solutions for n=5
..0..1..1..1..1. .0..0..0..0..0. .0..0..0..0..0. .0..1..1..1..1
..0..1..1..1..1. .0..1..0..0..0. .0..0..0..0..0. .1..1..1..1..0
..0..1..1..1..1. .0..0..0..0..0. .0..0..0..0..0. .1..1..1..0..0
..0..1..1..1..1. .0..0..0..0..0. .0..0..1..0..0. .1..1..0..0..0
..0..1..1..1..0. .1..1..1..1..1. .0..0..0..0..0. .1..0..0..0..0

Crossrefs

Cf. A318343.

Sequence in context: A027107 A247307 A279215 * A264307 A050930 A074353

Adjacent sequences: A318334 A318335 A318336 * A318338 A318339 A318340

Keyword

nonn

Author

R. H. Hardin, Aug 24 2018

Status

approved