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%I #4 May 11 2016 14:52:51
%S 4,21,24,60,210,637,1840,5792,18556,54034,160246,499140,1501706,
%T 4627363,13954490,43064736,131174878,399170874,1222825766,3739040310,
%U 11456400210,35068696769,107362206600,329271410590,1009129910706,3096269613087
%N Number of nX4 0..1 arrays with exactly n+4-2 having value 1 and no three 1s forming an isosceles right triangle.
%C Column 4 of A272958.
%H R. H. Hardin, <a href="/A272954/b272954.txt">Table of n, a(n) for n = 1..110</a>
%e Some solutions for n=5
%e ..0..1..1..0. .1..0..0..1. .0..0..1..1. .0..1..1..1. .1..0..1..0
%e ..1..0..0..1. .0..1..1..0. .0..0..0..0. .0..0..0..0. .0..0..0..1
%e ..0..0..0..0. .0..0..0..0. .1..0..0..1. .0..0..1..0. .0..0..0..1
%e ..1..0..0..1. .0..0..0..0. .1..0..1..0. .0..0..0..1. .0..0..1..0
%e ..0..1..0..0. .1..0..1..1. .1..0..0..0. .0..1..0..1. .1..1..0..0
%Y Cf. A272958.
%K nonn
%O 1,1
%A _R. H. Hardin_, May 11 2016