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 A281568 Number of 6Xn 0..1 arrays with no element equal to more than two of its horizontal, diagonal or antidiagonal neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards. 1

%I

%S 0,310,18020,53568,154722,347316,692421,1275888,2241388,3864672,

%T 6600534,11152312,18730106,31334466,52215554,86771200,143873022,

%U 237945548,392609350,646423526,1062014984,1741176780,2849127546,4653300102

%N Number of 6Xn 0..1 arrays with no element equal to more than two of its horizontal, diagonal or antidiagonal neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards.

%C Row 6 of A281563.

%H R. H. Hardin, <a href="/A281568/b281568.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 6*a(n-1) -15*a(n-2) +23*a(n-3) -30*a(n-4) +36*a(n-5) -31*a(n-6) +12*a(n-7) +9*a(n-8) -23*a(n-9) +33*a(n-10) -36*a(n-11) +23*a(n-12) -3*a(n-13) -9*a(n-14) +12*a(n-15) -12*a(n-16) +9*a(n-17) -2*a(n-18) -3*a(n-19) +3*a(n-20) -a(n-21) for n>37

%e Some solutions for n=4

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

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

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

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

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

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

%Y Cf. A281563.

%K nonn

%O 1,2

%A _R. H. Hardin_, Jan 24 2017

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Last modified January 17 05:13 EST 2022. Contains 350378 sequences. (Running on oeis4.)