A297088 - OEIS

A297088

Number of n X 2 0..1 arrays with no 1 adjacent to 3 king-move neighboring 1s.

4, 15, 45, 152, 511, 1681, 5588, 18575, 61621, 204608, 679407, 2255577, 7488924, 24864735, 82554557, 274095080, 910042783, 3021494049, 10031871012, 33307511407, 110586567109, 367166113104, 1219053634447, 4047464337257

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

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

FORMULA

Empirical: a(n) = 4*a(n-1) - 2*a(n-2) + 3*a(n-3) - 14*a(n-4) + 4*a(n-5).

Empirical g.f.: x*(4 - x - 7*x^2 - 10*x^3 + 4*x^4) / (1 - 4*x + 2*x^2 - 3*x^3 + 14*x^4 - 4*x^5). - Colin Barker, Feb 26 2019

EXAMPLE

Some solutions for n=7:

..1..0. .1..1. .1..0. .0..1. .1..1. .0..0. .0..1. .0..1. .1..0. .0..0

..0..0. .0..1. .0..0. .0..0. .0..0. .0..1. .1..0. .1..0. .1..0. .1..0

..0..0. .1..1. .1..1. .0..1. .1..0. .1..1. .0..0. .0..0. .0..0. .0..0

..1..0. .1..1. .0..0. .0..0. .0..0. .0..0. .1..0. .1..0. .1..0. .0..1

..0..1. .1..1. .0..1. .1..0. .0..0. .1..0. .1..0. .1..0. .0..0. .0..0

..1..0. .0..1. .1..1. .1..0. .1..0. .0..0. .0..0. .0..0. .0..1. .0..1

..1..0. .0..0. .0..0. .0..0. .0..0. .1..0. .1..0. .0..0. .1..1. .1..1

CROSSREFS

Column 2 of A297094.

Sequence in context: A075673 A062827 A074448 * A152116 A195688 A111038

Adjacent sequences: A297085 A297086 A297087 * A297089 A297090 A297091

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 25 2017

STATUS

approved