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A303620 Number of nX4 0..1 arrays with every element equal to 0, 2, 3, 4, 5 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

%I A303620 #4 Apr 27 2018 09:52:51
%S A303620 1,20,68,325,1870,10741,62207,363485,2135551,12586013,74323727,
%T A303620 439462339,2600501501,15395919313,91177465195,540072985865,
%U A303620 3199404347759,18954749501705,112301887289875,665378205627245,3942374534440139
%N A303620 Number of nX4 0..1 arrays with every element equal to 0, 2, 3, 4, 5 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
%C A303620 Column 4 of A303624.
%H A303620 R. H. Hardin, <a href="/A303620/b303620.txt">Table of n, a(n) for n = 1..210</a>
%F A303620 Empirical: a(n) = 9*a(n-1) -19*a(n-2) +19*a(n-3) -91*a(n-4) +33*a(n-5) -46*a(n-6) +295*a(n-7) +125*a(n-8) +527*a(n-9) -181*a(n-10) -44*a(n-11) -219*a(n-12) -360*a(n-13) +52*a(n-14) -131*a(n-15) -93*a(n-16) +23*a(n-17) +10*a(n-18) +70*a(n-19) +14*a(n-20) -16*a(n-21) +24*a(n-22) for n>24
%e A303620 Some solutions for n=5
%e A303620 ..0..1..1..1. .0..0..0..0. .0..1..1..0. .0..1..1..0. .0..1..1..0
%e A303620 ..0..1..1..1. .0..0..0..0. .1..1..1..1. .1..1..1..0. .1..1..1..0
%e A303620 ..0..1..1..1. .1..0..0..1. .1..1..1..0. .1..1..1..1. .1..1..1..1
%e A303620 ..1..1..1..1. .1..0..0..1. .0..1..1..1. .0..0..1..0. .0..1..0..0
%e A303620 ..0..1..1..1. .0..0..0..1. .1..1..1..1. .0..0..1..0. .0..1..0..0
%Y A303620 Cf. A303624.
%K A303620 nonn
%O A303620 1,2
%A A303620 _R. H. Hardin_, Apr 27 2018