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A208254 Number of n X 4 0..2 arrays with new values 0..2 introduced in row major order and no element equal to more than one of its immediate leftward or upward neighbors.

%I A208254 #8 Jun 29 2018 08:05:00
%S A208254 14,768,43344,2445264,137947632,7782199824,439026252912,
%T A208254 24767296501776,1397226183866736,78823339024454928,
%U A208254 4446752320207192176,250859789016717819408,14152043831975777230704,798375640062491402594064
%N A208254 Number of n X 4 0..2 arrays with new values 0..2 introduced in row major order and no element equal to more than one of its immediate leftward or upward neighbors.
%C A208254 Column 4 of A208258.
%H A208254 R. H. Hardin, <a href="/A208254/b208254.txt">Table of n, a(n) for n = 1..210</a>
%F A208254 Empirical: a(n) = 61*a(n-1) - 266*a(n-2) + 416*a(n-3) - 256*a(n-4) for n>5.
%F A208254 Empirical g.f.: 2*x*(7 - 43*x + 110*x^2 - 128*x^3 + 64*x^4) / (1 - 61*x + 266*x^2 - 416*x^3 + 256*x^4). - _Colin Barker_, Jun 29 2018
%e A208254 Some solutions for n=4
%e A208254 ..0..0..0..0....0..0..0..1....0..0..1..2....0..1..0..2....0..0..0..0
%e A208254 ..1..0..1..0....2..0..1..0....0..2..2..0....1..2..2..1....1..2..2..2
%e A208254 ..2..1..0..1....0..2..1..1....2..0..0..1....1..0..1..2....1..2..1..1
%e A208254 ..2..0..1..0....2..0..0..1....2..1..2..1....0..1..2..0....1..2..1..2
%Y A208254 Cf. A208258.
%K A208254 nonn
%O A208254 1,1
%A A208254 _R. H. Hardin_, Feb 24 2012