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A269272 Number of n X 4 0..3 arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling three exactly once. 1

%I

%S 108,13896,1104264,74853576,4684312584,279339197256,16128206816904,

%T 909870855444936,50443519266217224,2758864964165996616,

%U 149253876730080113544,8002845140585293252296,425920265748436386105864

%N Number of n X 4 0..3 arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling three exactly once.

%H R. H. Hardin, <a href="/A269272/b269272.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 98*a(n-1) - 2401*a(n-2) for n > 3.

%F Conjectures from _Colin Barker_, Jan 20 2019: (Start)

%F G.f.: 36*x*(3 + 92*x + 49*x^2) / (1 - 49*x)^2.

%F a(n) = 72 * 49^(n-2) * (120*n-47) for n>1.

%F (End)

%e Some solutions for n=2:

%e 3 2 2 0 1 1 0 0 3 0 2 3 0 2 0 3 2 2 3 2

%e 2 2 3 2 1 3 2 0 2 0 1 0 2 2 2 3 0 2 3 0

%Y Column 4 of A269276.

%K nonn

%O 1,1

%A _R. H. Hardin_, Feb 21 2016

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Last modified February 3 02:33 EST 2023. Contains 360024 sequences. (Running on oeis4.)