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A207545 Number of nX3 0..2 arrays avoiding the pattern z-2 z-1 z in any row, column, nw-to-se diagonal or ne-to-sw antidiagonal.

%I A207545 #9 Jul 22 2025 20:33:54
%S A207545 26,676,14974,327899,7104784,153718531,3323115736,71828785449,
%T A207545 1552463878141,33553506212607,725189754458127,15673455950921338,
%U A207545 338748698841773309,7321337736630455158,158235245543724632042
%N A207545 Number of nX3 0..2 arrays avoiding the pattern z-2 z-1 z in any row, column, nw-to-se diagonal or ne-to-sw antidiagonal.
%C A207545 Column 3 of A207550
%H A207545 R. H. Hardin, <a href="/A207545/b207545.txt">Table of n, a(n) for n = 1..210</a>
%F A207545 Empirical: a(n) = 25*a(n-1) -14*a(n-2) -1439*a(n-3) +2416*a(n-4) +24494*a(n-5) -42148*a(n-6) -155315*a(n-7) +298717*a(n-8) +465648*a(n-9) -796742*a(n-10) -772730*a(n-11) -248746*a(n-12) +448619*a(n-13) +4500187*a(n-14) +1535833*a(n-15) -6305900*a(n-16) -2969844*a(n-17) +2515810*a(n-18) +1396963*a(n-19) +20165*a(n-20) +11517*a(n-21) -177480*a(n-22) -113665*a(n-23) +8548*a(n-24) +5517*a(n-25) +252*a(n-26)
%e A207545 Some solutions for n=4
%e A207545 ..0..0..2....2..2..2....2..1..0....2..0..1....2..1..0....2..2..1....1..2..2
%e A207545 ..0..0..2....1..2..1....0..1..1....2..0..2....2..1..2....2..0..0....0..0..1
%e A207545 ..0..0..0....0..2..2....1..0..0....2..0..2....0..1..1....2..0..0....1..2..0
%e A207545 ..1..2..0....0..0..2....1..2..2....2..0..1....0..1..1....2..2..2....1..2..1
%K A207545 nonn
%O A207545 1,1
%A A207545 _R. H. Hardin_ Feb 18 2012