%I
%S 20,166,537,1358,3137,6838,14375,29416,58984,116466,227134,438532,
%T 839659,1596460,3017310,5673426,10619999,19801344,36791933,68149580,
%U 125882603,231941798,426388234,782226746,1432314394,2618121324,4778002317
%N Number of n X 7 0..1 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.
%H R. H. Hardin, <a href="/A281204/b281204.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 4*a(n1)  4*a(n2)  2*a(n4) + 4*a(n5)  2*a(n6) + 4*a(n7)  a(n8)  2*a(n10)  a(n12).
%F Empirical g.f.: x*(20 + 86*x  47*x^2  126*x^3  107*x^4  26*x^5 + 21*x^6 + 88*x^7 + 92*x^8 + 56*x^9 + 23*x^10 + 10*x^11) / ((1  2*x + x^2  x^3)^2*(1  x^2  x^3)^2).  _Colin Barker_, Feb 18 2019
%e Some solutions for n=4:
%e ..0..1..0..0..1..1..0. .0..1..0..0..1..0..1. .0..1..0..0..1..0..0
%e ..0..1..1..0..1..0..1. .0..1..1..0..1..0..1. .0..1..1..0..1..1..0
%e ..0..0..1..0..1..0..0. .0..0..1..0..1..1..0. .1..0..1..0..0..1..1
%e ..1..0..1..0..1..1..0. .1..0..1..0..1..0..1. .1..0..1..1..0..0..1
%Y Column 7 of A281205.
%K nonn
%O 1,1
%A _R. H. Hardin_, Jan 17 2017
