%I #7 Oct 19 2021 21:25:21
%S 1970,73133,1782191,35625711,600064928,9098547899,131428029860,
%T 1883474084204,27236695360128,398320420587108,5870939348495954,
%U 86941313422965979,1290991288648976502,19200795902731377026
%N Number of (n+1) X 4 0..2 arrays with rows and columns of determinants of all 2 X 2 subblocks lexicographically nondecreasing.
%C Column 3 of A206223.
%H R. H. Hardin, <a href="/A206218/b206218.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 42*a(n-1) -625*a(n-2) +2990*a(n-3) +19429*a(n-4) -300482*a(n-5) +1205989*a(n-6) +739674*a(n-7) -21921768*a(n-8) +68928624*a(n-9) -44135280*a(n-10) -218575584*a(n-11) +570862080*a(n-12) -547928064*a(n-13) +191102976*a(n-14) for n > 30.
%e Some solutions for n=4
%e ..0..1..0..1....2..0..0..1....2..2..0..1....1..2..1..2....0..0..2..1
%e ..2..0..0..0....2..0..0..1....1..0..0..1....1..1..0..2....2..0..2..1
%e ..1..0..1..1....2..0..0..0....1..0..0..0....1..1..2..2....1..0..1..1
%e ..1..0..2..2....0..0..0..1....1..2..1..0....1..2..1..1....2..0..1..2
%e ..2..2..0..0....0..0..0..2....0..2..2..2....0..2..1..1....1..0..0..1
%Y Cf. A206223.
%K nonn
%O 1,1
%A _R. H. Hardin_ Feb 04 2012