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A281202 Number of n X 5 0..1 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards. 1

%I #8 Feb 17 2019 16:55:02

%S 5,52,176,470,1141,2602,5712,12208,25577,52784,107636,217370,435473,

%T 866550,1714460,3375236,6616061,12919308,25142632,48783294,94395997,

%U 182209890,350933080,674521464,1294078657,2478473672,4739410828

%N Number of n X 5 0..1 arrays with no element equal to more than one of its horizontal 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="/A281202/b281202.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 4*a(n-1) - 4*a(n-2) - 2*a(n-4) + 4*a(n-5) - a(n-8).

%F Empirical g.f.: x*(5 + 32*x - 12*x^2 - 26*x^3 - 25*x^4 + 2*x^5 + 12*x^6 + 4*x^7) / ((1 - x)^2*(1 - x - x^2 - x^3)^2). - _Colin Barker_, Feb 17 2019

%e Some solutions for n=4:

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

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

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

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

%Y Column 5 of A281205.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 17 2017

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Last modified April 25 12:32 EDT 2024. Contains 371969 sequences. (Running on oeis4.)