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A317819 Number of nX4 0..1 arrays with every element unequal to 1, 2 or 3 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero. 1

%I #4 Aug 07 2018 22:05:48

%S 2,50,135,702,2726,11768,48526,203049,846901,3533862,14751288,

%T 61572336,256988741,1072703816,4477368403,18688452762,78005403965,

%U 325591740543,1359014862402,5672494506043,23676864307080,98826717050870

%N Number of nX4 0..1 arrays with every element unequal to 1, 2 or 3 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

%C Column 4 of A317823.

%H R. H. Hardin, <a href="/A317819/b317819.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = a(n-1) +20*a(n-2) +6*a(n-3) -154*a(n-4) -117*a(n-5) +672*a(n-6) +587*a(n-7) -2050*a(n-8) -1804*a(n-9) +3999*a(n-10) +3942*a(n-11) -2519*a(n-12) -5840*a(n-13) -9009*a(n-14) +8051*a(n-15) +33470*a(n-16) -7813*a(n-17) -52983*a(n-18) -121*a(n-19) +41444*a(n-20) +12853*a(n-21) -6529*a(n-22) -19825*a(n-23) -19439*a(n-24) +13134*a(n-25) +21223*a(n-26) -2212*a(n-27) -10933*a(n-28) -1301*a(n-29) +3458*a(n-30) +557*a(n-31) -769*a(n-32) -110*a(n-33) +103*a(n-34) +19*a(n-35) -11*a(n-36) +a(n-37) for n>43

%e Some solutions for n=5

%e ..0..1..0..1. .0..1..0..0. .0..1..1..0. .0..1..1..0. .0..1..1..1

%e ..1..0..0..1. .1..1..1..0. .0..1..1..0. .0..1..0..0. .1..1..0..0

%e ..0..0..0..0. .1..1..1..0. .0..1..1..1. .1..0..0..1. .0..0..0..0

%e ..1..0..0..1. .0..1..1..0. .1..1..1..1. .0..0..0..1. .0..0..1..1

%e ..1..1..1..0. .0..0..1..1. .0..0..0..1. .1..0..0..1. .1..1..1..0

%Y Cf. A317823.

%K nonn

%O 1,1

%A _R. H. Hardin_, Aug 07 2018

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Last modified February 21 22:50 EST 2024. Contains 370239 sequences. (Running on oeis4.)