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Number of nX3 0..1 arrays with no 1 equal to more than one of its horizontal, vertical and antidiagonal neighbors, with the exception of exactly one element.
1

%I #4 Feb 24 2017 07:44:54

%S 1,8,74,430,2426,13062,67676,342972,1707597,8384136,40716024,

%T 195950228,935955604,4442192472,20968437076,98509310972,460879910601,

%U 2148369624844,9981992555058,46244594782978,213681269956154,985012878231418

%N Number of nX3 0..1 arrays with no 1 equal to more than one of its horizontal, vertical and antidiagonal neighbors, with the exception of exactly one element.

%C Column 3 of A282885.

%H R. H. Hardin, <a href="/A282880/b282880.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 2*a(n-1) +17*a(n-2) +22*a(n-3) -75*a(n-4) -376*a(n-5) -834*a(n-6) -1206*a(n-7) -1229*a(n-8) -824*a(n-9) -187*a(n-10) +346*a(n-11) +511*a(n-12) +344*a(n-13) +91*a(n-14) -74*a(n-15) -106*a(n-16) -42*a(n-17) +2*a(n-18) +16*a(n-19) +4*a(n-20) -a(n-22)

%e Some solutions for n=4

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

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

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

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

%Y Cf. A282885.

%K nonn

%O 1,2

%A _R. H. Hardin_, Feb 24 2017