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

%I #4 Apr 03 2018 12:17:15

%S 0,3,14,45,146,537,1934,6861,24386,86913,309638,1102677,3927050,

%T 13986633,49814510,177416541,631877618,2250466449,8015156630,

%U 28546401765,101669514458,362101348953,1289643083966,4593131945709,16358681988674

%N Number of 2Xn 0..1 arrays with every element equal to 1, 2 or 3 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

%C Row 2 of A302224.

%H R. H. Hardin, <a href="/A302225/b302225.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 2*a(n-1) +3*a(n-2) +6*a(n-3) +10*a(n-4) +4*a(n-5) for n>6

%e Some solutions for n=5

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

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

%Y Cf. A302224.

%K nonn

%O 1,2

%A _R. H. Hardin_, Apr 03 2018