A283545 Number of 4 X n 0..1 arrays with no 1 equal to more than one of its horizontal, diagonal and antidiagonal neighbors.

16, 98, 573, 4089, 25532, 167920, 1094959, 7101809, 46326550, 301306398, 1961384325, 12768156061, 83100368446, 540929424728, 3520893704293, 22917627167529, 149172500835242, 970968632009710, 6320086805449019

Offset

1,1

Links

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

Formula

Empirical: a(n) = 2*a(n-1) + 19*a(n-2) + 62*a(n-3) + 24*a(n-4) + 82*a(n-5) - 75*a(n-6) + 50*a(n-7) - 145*a(n-8).

Empirical g.f.: x*(16 + 66*x + 73*x^2 + 89*x^3 + 7*x^4 - 25*x^5 - 95*x^6 - 145*x^7) / (1 - 2*x - 19*x^2 - 62*x^3 - 24*x^4 - 82*x^5 + 75*x^6 - 50*x^7 + 145*x^8). - Colin Barker, Feb 21 2019

Example

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

Crossrefs

Row 4 of A283543.

Sequence in context: A264580 A122102 A214612 * A297684 A344866 A322722

Adjacent sequences: A283542 A283543 A283544 * A283546 A283547 A283548

Keyword

nonn

Author

R. H. Hardin, Mar 10 2017

Status

approved