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Number of 3 X n 0..1 arrays with every element equal to 0, 1, 3 or 4 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
1

%I #6 Sep 03 2022 21:42:28

%S 4,6,13,26,48,121,275,600,1296,2998,6731,15022,33412,75480,169232,

%T 379265,848913,1907065,4276079,9589159,21494910,48224727,108142434,

%U 242526545,543834226,1219737296,2735350513,6134430103,13756843652,30852213480

%N Number of 3 X n 0..1 arrays with every element equal to 0, 1, 3 or 4 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

%C Row 3 of A302309.

%H R. H. Hardin, <a href="/A302311/b302311.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = a(n-1) +3*a(n-2) -a(n-3) +8*a(n-4) -7*a(n-5) -22*a(n-6) +9*a(n-7) -14*a(n-8) +10*a(n-9) +39*a(n-10) -19*a(n-11) +6*a(n-12) -18*a(n-14) +9*a(n-15) for n>16.

%e Some solutions for n=5

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

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

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

%Y Cf. A302309.

%K nonn

%O 1,1

%A _R. H. Hardin_, Apr 05 2018