A279896 Number of n X 2 0..2 arrays with no element unequal to a strict majority of its king-move neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.

0, 4, 6, 8, 18, 36, 78, 160, 338, 700, 1462, 3032, 6298, 13044, 27006, 55824, 115298, 237868, 490310, 1009736, 2077738, 4271972, 8776974, 18019968, 36972018, 75808156, 155344598, 318145720, 651204538, 1332235220, 2724122782, 5567550192

Offset

1,2

Links

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

Formula

Empirical: a(n) = 2*a(n-1) + 3*a(n-2) - 4*a(n-3) - 4*a(n-4) for n>7.

Empirical g.f.: 2*x^2*(1 - 2*x^2)*(2 - x - 4*x^2 - 2*x^3) / ((1 + x)^2*(1 - 2*x)^2). - Colin Barker, Feb 12 2019

Example

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

Crossrefs

Column 2 of A279902.

Sequence in context: A132040 A210459 A346868 * A247280 A226237 A114315

Adjacent sequences: A279893 A279894 A279895 * A279897 A279898 A279899

Keyword

nonn

Author

R. H. Hardin, Dec 22 2016

Status

approved