%I #8 Jul 19 2023 09:39:54
%S 22,1849,109119,6092872,348151747,19914296913,1137589582096,
%T 64992189188797,3713325091122745,212156302986486914,
%U 12121270553957772787,692534079965581463725,39567093279061401381682,2260617527909089482464661
%N Number of nX4 0..2 arrays with every nonzero element less than or equal to some horizontal or vertical neighbor.
%H R. H. Hardin, <a href="/A202885/b202885.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 58*a(n-1) -409*a(n-2) +19812*a(n-3) -7455*a(n-4) +2592909*a(n-5) +12335100*a(n-6) -16921246*a(n-7) -80782159*a(n-8) -4256903692*a(n-9) -15824503819*a(n-10) +51444732070*a(n-11) +665973079452*a(n-12) +1722193958142*a(n-13) -9381699323187*a(n-14) -52231180624458*a(n-15) -96373950069860*a(n-16) +536481249758489*a(n-17) +2646445223858022*a(n-18) -2670449971660545*a(n-19) -23685322388362288*a(n-20) +5273037676253028*a(n-21) +123562120872374900*a(n-22) +14554488540108224*a(n-23) -423772107328693168*a(n-24) -137361850647059616*a(n-25) +951983290636001856*a(n-26) +456183082446901248*a(n-27) -1309658113153668096*a(n-28) -798409204703133696*a(n-29) +997927647389908992*a(n-30) +720498553714114560*a(n-31) -407490029986775040*a(n-32) -334751276287918080*a(n-33) +70526354545704960*a(n-34) +67405719388815360*a(n-35)
%e Some solutions for n=2
%e ..0..2..2..0....2..0..2..2....0..0..1..1....2..2..0..0....1..2..1..1
%e ..0..0..1..0....2..1..1..1....0..0..1..1....1..1..1..0....0..2..0..1
%Y Column 4 of A202889.
%K nonn
%O 1,1
%A _R. H. Hardin_, Dec 25 2011