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Number of nX3 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 2 or 3 neighboring 1s.
1

%I #4 Dec 31 2017 15:00:07

%S 1,11,35,88,461,2050,8057,35640,158090,679629,2963173,12981912,

%T 56560118,246687460,1077347659,4701310128,20514731834,89541862920,

%U 390793087220,1705499848917,7443466123759,32485974265409,141779148752373

%N Number of nX3 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 2 or 3 neighboring 1s.

%C Column 3 of A297544.

%H R. H. Hardin, <a href="/A297539/b297539.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 3*a(n-1) +38*a(n-3) -40*a(n-4) +7*a(n-5) -296*a(n-6) +98*a(n-7) +36*a(n-8) +388*a(n-9) -96*a(n-10) -104*a(n-11) +400*a(n-12) -192*a(n-13) +128*a(n-14)

%e Some solutions for n=5

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

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

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

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

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

%Y Cf. A297544.

%K nonn

%O 1,2

%A _R. H. Hardin_, Dec 31 2017