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A303243 Number of 3Xn 0..1 arrays with every element equal to 0, 2, 3, 5 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero. 1

%I

%S 4,2,18,8,60,56,236,428,1248,3264,8624,24720,65816,187464,509576,

%T 1428608,3932112,10932480,30245800,83854984,232353544,643805072,

%U 1784418352,4944349600,13703715720,37974373160,105243781928,291657188656

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

%C Row 3 of A303242.

%H R. H. Hardin, <a href="/A303243/b303243.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 3*a(n-1) +9*a(n-2) -28*a(n-3) -37*a(n-4) +117*a(n-5) +85*a(n-6) -280*a(n-7) -118*a(n-8) +424*a(n-9) +92*a(n-10) -428*a(n-11) -26*a(n-12) +300*a(n-13) +12*a(n-14) -172*a(n-15) +48*a(n-16) +24*a(n-17) -48*a(n-18) +8*a(n-20)

%e Some solutions for n=5

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

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

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

%Y Cf. A303242.

%K nonn

%O 1,1

%A _R. H. Hardin_, Apr 20 2018

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Last modified October 18 01:39 EDT 2021. Contains 348065 sequences. (Running on oeis4.)