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A208861 Number of nX5 0..3 arrays with new values 0..3 introduced in row major order and no element equal to more than one of its immediate leftward or upward or left-upward diagonal neighbors.

%I A208861 #7 Jul 22 2025 21:31:53
%S A208861 51,23047,12883280,7240366702,4071491223248,2289701830963879,
%T A208861 1287681340443915644,724166398812363542260,407256849342915985761092,
%U A208861 229033195050822330468202369,128803738036903910358389563556
%N A208861 Number of nX5 0..3 arrays with new values 0..3 introduced in row major order and no element equal to more than one of its immediate leftward or upward or left-upward diagonal neighbors.
%C A208861 Column 5 of A208864
%H A208861 R. H. Hardin, <a href="/A208861/b208861.txt">Table of n, a(n) for n = 1..210</a>
%F A208861 Empirical: a(n) = 831*a(n-1) -179993*a(n-2) +17822337*a(n-3) -914949819*a(n-4) +23168761555*a(n-5) -161356715633*a(n-6) -4487021565447*a(n-7) +88170625092243*a(n-8) -89146256087223*a(n-9) -9123849468343275*a(n-10) +57411954474413179*a(n-11) +280936943350232287*a(n-12) -3595338835588287543*a(n-13) +1929659835323795485*a(n-14) +90093226296032329771*a(n-15) -288134852946702870262*a(n-16) -742914836218346528932*a(n-17) +7115855576376274368216*a(n-18) -24955774603971431557536*a(n-19) +63937383750208880620992*a(n-20) -111375370598187857506560*a(n-21) +72057203548966403859456*a(n-22) +76274285418217337610240*a(n-23) -111975434876548575756288*a(n-24) +5300659781619687751680*a(n-25) +29374280040899283517440*a(n-26) -7836898836947747733504*a(n-27) for n>28
%e A208861 Some solutions for n=4
%e A208861 ..0..0..0..0..1....0..0..0..0..0....0..1..0..0..0....0..1..1..0..0
%e A208861 ..1..1..1..2..1....0..1..1..2..2....1..0..1..1..1....0..1..2..0..1
%e A208861 ..2..3..0..1..2....2..2..3..2..3....1..0..2..3..2....3..2..3..1..2
%e A208861 ..0..0..1..3..0....3..1..1..2..1....3..2..3..1..1....2..0..1..0..0
%K A208861 nonn
%O A208861 1,1
%A A208861 _R. H. Hardin_ Mar 02 2012