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Number of nX3 0..1 arrays with each 1 adjacent to 3, 4 or 6 king-move neighboring 1s.
1

%I #4 Dec 23 2017 15:02:17

%S 1,3,8,14,39,135,400,1310,4481,15005,50813,173538,590268,2009778,

%T 6857427,23374979,79672060,271719009,926494874,3158768148,10771237589,

%U 36728205113,125230802047,427013571111,1456037283696,4964723542111

%N Number of nX3 0..1 arrays with each 1 adjacent to 3, 4 or 6 king-move neighboring 1s.

%C Column 3 of A297020.

%H R. H. Hardin, <a href="/A297015/b297015.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = a(n-1) +5*a(n-2) +22*a(n-3) -3*a(n-4) -80*a(n-5) -161*a(n-6) -18*a(n-7) +288*a(n-8) +466*a(n-9) +118*a(n-10) -275*a(n-11) -312*a(n-12) +63*a(n-13) +36*a(n-14) -124*a(n-15) -134*a(n-16) +22*a(n-17) +68*a(n-18) -17*a(n-19) -20*a(n-20)

%e Some solutions for n=7

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

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

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

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

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

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

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

%Y Cf. A297020.

%K nonn

%O 1,2

%A _R. H. Hardin_, Dec 23 2017