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A233143 Number of nX4 0..5 arrays with no element x(i,j) adjacent to value 5-x(i,j) horizontally, antidiagonally or vertically, top left element zero, and 1 appearing before 2 3 and 4, and 2 appearing before 3 in row major order.

%I A233143 #6 Jul 23 2025 07:54:52
%S A233143 23,3727,845917,198313130,46648134615,10976545771938,2582927810338210,
%T A233143 607799571521107132,143023917159921251486,33655571006177475521033,
%U A233143 7919636704985653736563452,1863603667625659594920136702
%N A233143 Number of nX4 0..5 arrays with no element x(i,j) adjacent to value 5-x(i,j) horizontally, antidiagonally or vertically, top left element zero, and 1 appearing before 2 3 and 4, and 2 appearing before 3 in row major order.
%C A233143 Column 4 of A233147
%H A233143 R. H. Hardin, <a href="/A233143/b233143.txt">Table of n, a(n) for n = 1..210</a>
%F A233143 Empirical: a(n) = 310*a(n-1) -19831*a(n-2) +567817*a(n-3) -9045239*a(n-4) +90083339*a(n-5) -602192427*a(n-6) +2821467285*a(n-7) -9491948537*a(n-8) +23238614757*a(n-9) -41808469376*a(n-10) +55264690349*a(n-11) -51692358938*a(n-12) +30252784146*a(n-13) -5648166713*a(n-14) -6372298968*a(n-15) +4876472605*a(n-16) -104115359*a(n-17) -1424089179*a(n-18) +752282173*a(n-19) -147512539*a(n-20) -22839*a(n-21) +3406138*a(n-22) -81513*a(n-23) -44431*a(n-24) -3578*a(n-25) +468*a(n-26) +81*a(n-27) for n>28
%e A233143 Some solutions for n=2
%e A233143 ..0..1..2..1....0..1..0..4....0..0..1..0....0..1..1..2....0..1..0..1
%e A233143 ..3..5..2..2....1..1..0..2....2..1..0..0....3..5..1..1....1..1..2..5
%K A233143 nonn
%O A233143 1,1
%A A233143 _R. H. Hardin_, Dec 04 2013