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Number of n X 5 0..4 arrays with values 0..4 introduced in row major order and no element equal to any horizontal or vertical neighbor.
2

%I #7 May 14 2021 15:24:57

%S 15,4801,2125425,948656912,423503301834,189062985604305,

%T 84402688527136201,37679579867128064832,16821155393975907014458,

%U 7509406150309683843851949,3352396396661126098060061297

%N Number of n X 5 0..4 arrays with values 0..4 introduced in row major order and no element equal to any horizontal or vertical neighbor.

%C Column 5 of A198906.

%H R. H. Hardin, <a href="/A198903/b198903.txt">Table of n, a(n) for n = 1..200</a>

%F Empirical: a(n) = 559*a(n-1) -54943*a(n-2) +2182857*a(n-3) -41132051*a(n-4) +348302393*a(n-5) -519526889*a(n-6) -11351340633*a(n-7) +79466721924*a(n-8) -227367989480*a(n-9) +329414183656*a(n-10) -247117199296*a(n-11) +89130224384*a(n-12) -11964372480*a(n-13).

%e Some solutions with values 0 to 4 for n=4

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

%e ..1..0..2..0..2....1..0..3..4..0....1..0..2..3..4....1..0..2..1..4

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

%e ..1..0..4..2..1....1..0..3..2..3....1..0..2..1..4....1..0..3..1..4

%Y Cf. A198906.

%K nonn

%O 1,1

%A _R. H. Hardin_ Oct 31 2011