A279263 Number of n X 3 0..1 arrays with no element equal to a strict majority of its horizontal and vertical neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.

2, 10, 29, 86, 240, 626, 1603, 4030, 9973, 24388, 59068, 141920, 338689, 803630, 1897359, 4460226, 10444904, 24376990, 56720671, 131619998, 304674313, 703690416, 1621976820, 3731637260, 8570604669, 19653441614, 45002040707

Offset

1,1

Links

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

Formula

Empirical: a(n) = 4*a(n-1) - 4*a(n-2) + 2*a(n-3) - 4*a(n-4) - a(n-6) for n>9.

Empirical g.f.: x*(2 + 2*x - 3*x^2 + 6*x^3 - 8*x^5 + 5*x^6 - 4*x^7 + 2*x^8) / (1 - 2*x - x^3)^2. - Colin Barker, Feb 10 2019

Example

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

Crossrefs

Column 3 of A279268.

Sequence in context: A192976 A264677 A101561 * A295525 A302274 A047112

Adjacent sequences: A279260 A279261 A279262 * A279264 A279265 A279266

Keyword

nonn

Author

R. H. Hardin, Dec 08 2016

Status

approved