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A279460 Number of n X 2 0..1 arrays with no element equal to a strict majority of its horizontal, vertical and antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards. 1

%I #9 Feb 11 2019 05:20:04

%S 0,2,6,20,66,210,658,2036,6236,18928,57032,170790,508748,1508462,

%T 4454576,13107640,38446722,112448726,328044512,954771282,2772970950,

%U 8038036642,23258558892,67190053760,193807573324,558249440024,1605908314802

%N Number of n X 2 0..1 arrays with no element equal to a strict majority of its horizontal, vertical and antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.

%H R. H. Hardin, <a href="/A279460/b279460.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 4*a(n-1) - 2*a(n-2) - 3*a(n-4) - 14*a(n-5) - 14*a(n-6) - 14*a(n-7) - 13*a(n-8) - 6*a(n-9) - a(n-10).

%F Empirical g.f.: 2*x^2*(1 + x)*(1 - 2*x + 2*x^2 - 3*x^3 - x^4 - x^5 - x^6) / (1 - 2*x - x^2 - 2*x^3 - 3*x^4 - x^5)^2. - _Colin Barker_, Feb 11 2019

%e Some solutions for n=4:

%e ..0..1. .0..0. .0..1. .0..0. .0..1. .0..1. .0..1. .0..0. .0..0. .0..0

%e ..0..0. .1..0. .0..0. .1..1. .0..1. .1..0. .1..0. .1..0. .1..0. .1..0

%e ..1..0. .1..0. .0..1. .0..1. .0..1. .0..1. .1..0. .0..1. .0..1. .1..1

%e ..1..1. .1..0. .1..0. .0..0. .0..0. .0..0. .1..1. .0..1. .1..0. .0..0

%Y Column 2 of A279466.

%K nonn

%O 1,2

%A _R. H. Hardin_, Dec 12 2016

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Last modified April 19 05:19 EDT 2024. Contains 371782 sequences. (Running on oeis4.)