%I #4 Mar 29 2018 12:43:10
%S 2,16,123,947,7326,56710,439078,3399722,26323903,203825456,1578217598,
%T 12220118582,94620225492,732643232114,5672847473255,43924787764759,
%U 340109088005893,2633460459021237,20390851741033347,157886112662767667
%N Number of nX4 0..1 arrays with every element equal to 1, 2 or 3 horizontally or antidiagonally adjacent elements, with upper left element zero.
%C Column 4 of A301951.
%H R. H. Hardin, <a href="/A301947/b301947.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 9*a(n-1) -8*a(n-2) -14*a(n-3) +4*a(n-4) +4*a(n-5) -a(n-6)
%e Some solutions for n=5
%e ..0..0..1..0. .0..0..1..1. .0..0..1..1. .0..0..0..0. .0..0..0..0
%e ..0..1..0..1. .0..0..1..1. .1..1..0..1. .0..0..1..1. .0..1..0..1
%e ..0..0..1..1. .0..0..0..1. .1..0..1..1. .0..1..1..1. .1..0..1..1
%e ..0..1..0..0. .1..1..1..0. .0..0..0..1. .1..0..1..0. .0..0..1..0
%e ..0..0..0..0. .1..1..0..0. .1..1..1..1. .0..1..0..0. .0..0..0..0
%Y Cf. A301951.
%K nonn
%O 1,1
%A _R. H. Hardin_, Mar 29 2018