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Number of nX4 0..1 arrays with every element equal to 0, 1 or 4 horizontally or antidiagonally adjacent elements, with upper left element zero.
1

%I #4 Mar 29 2018 12:59:22

%S 5,9,25,64,169,441,1156,3025,7921,20736,54289,142129,372100,974169,

%T 2550409,6677056,17480761,45765225,119814916,313679521,821223649,

%U 2149991424,5628750625,14736260449,38580030724,101003831721,264431464441

%N Number of nX4 0..1 arrays with every element equal to 0, 1 or 4 horizontally or antidiagonally adjacent elements, with upper left element zero.

%C Column 4 of A301964.

%H R. H. Hardin, <a href="/A301960/b301960.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 2*a(n-1) +2*a(n-2) -a(n-3) for n>4

%e Some solutions for n=5

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

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

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

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

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

%Y Cf. A301964.

%K nonn

%O 1,1

%A _R. H. Hardin_, Mar 29 2018