A296391 - OEIS

%I #4 Dec 11 2017 13:59:21

%S 3,11,36,115,387,1280,4237,14026,46454,153800,509255,1686210,5583282,

%T 18486920,61212645,202682982,671109638,2222130975,7357763936,

%U 24362510288,80667430752,267100323021,884403804216,2928375674093,9696231573791

%N Number of nX3 0..1 arrays with each 1 horizontally, vertically or antidiagonally adjacent to 1 or 3 neighboring 1s.

%C Column 3 of A296396.

%H R. H. Hardin, <a href="/A296391/b296391.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 2*a(n-1) +4*a(n-2) +2*a(n-3) -3*a(n-4) -2*a(n-5) +7*a(n-6) +4*a(n-7) +a(n-8) -14*a(n-9) +10*a(n-11) -3*a(n-12) -2*a(n-13) +a(n-14)

%e Some solutions for n=5

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

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

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

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

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

%Y Cf. A296396.

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 11 2017