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%I #8 Feb 28 2019 16:20:42
%S 3,17,49,177,727,2445,8931,33841,120079,438161,1618767,5849585,
%T 21333063,78146401,284124279,1036090465,3784306647,13787045553,
%U 50277043559,183451730433,668806025271,2438991559953,8896352148007,32440479868961
%N Number of n X 3 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 1 or 3 neighboring 1s.
%H R. H. Hardin, <a href="/A297514/b297514.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = a(n-1) + 2*a(n-2) + 30*a(n-3) + 6*a(n-5) - 124*a(n-6) - 8*a(n-8) + 64*a(n-9).
%F Empirical g.f.: x*(3 + 14*x + 26*x^2 + 4*x^3 - 58*x^4 - 124*x^5 - 8*x^6 + 24*x^7 + 64*x^8) / (1 - x - 2*x^2 - 30*x^3 - 6*x^5 + 124*x^6 + 8*x^8 - 64*x^9). - _Colin Barker_, Feb 28 2019
%e Some solutions for n=7:
%e ..0..0..1. .1..0..1. .1..0..0. .1..0..0. .1..1..0. .0..0..0. .1..0..0
%e ..0..1..0. .1..1..0. .0..1..0. .1..1..0. .1..0..1. .0..0..0. .0..1..1
%e ..0..0..0. .0..0..0. .1..0..1. .0..0..1. .1..0..0. .0..0..0. .0..0..1
%e ..0..1..1. .1..1..1. .0..0..0. .0..0..0. .0..1..1. .0..1..1. .1..0..1
%e ..0..0..0. .1..0..0. .0..1..0. .1..1..0. .0..0..1. .0..0..0. .1..1..0
%e ..0..0..1. .1..0..0. .1..0..0. .0..0..0. .1..0..0. .1..1..0. .0..0..0
%e ..1..1..1. .0..1..0. .0..0..0. .0..0..0. .0..1..0. .1..0..1. .0..0..0
%Y Column 3 of A297519.
%K nonn
%O 1,1
%A _R. H. Hardin_, Dec 31 2017
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