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%I #6 Jun 08 2021 12:21:35
%S 480071296,326595297792,220722832237568,149185819914631168,
%T 100827647839987847168,68144762665642379485184,
%U 46055875906826738439045120,31127025414950384068108124160
%N Number of (n+2) X (3+2) 0..3 arrays with no increasing sequence of length 3 horizontally or antidiagonally downwards.
%C Column 3 of A233845.
%H R. H. Hardin, <a href="/A233840/b233840.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 676*a(n-1) +6980*a(n-2) -4863328*a(n-3) +41995792*a(n-4) +7953854528*a(n-5) -184904579136*a(n-6) +809889143808*a(n-7) +10973630976000*a(n-8) -119806280073216*a(n-9) +355504517218304*a(n-10) +141549729742848*a(n-11) -1945470193631232*a(n-12) +423049732030464*a(n-13) +1344200025047040*a(n-14) -382139212234752*a(n-15) +171684875206656*a(n-16).
%e Some solutions for n=1
%e ..0..0..0..1..0....0..0..0..1..0....0..0..0..1..0....0..0..0..0..0
%e ..0..2..1..2..2....1..0..0..2..1....1..2..0..1..0....1..2..0..1..1
%e ..0..2..1..2..0....2..2..2..3..0....1..2..1..0..3....2..1..0..1..0
%Y Cf. A233845.
%K nonn
%O 1,1
%A _R. H. Hardin_, Dec 16 2013