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A222921 Number of nX3 0..4 arrays with no three equal values in a row horizontally or vertically, and new values 0..4 introduced in row major order.

%I A222921 #6 Jul 23 2025 03:16:00
%S A222921 4,174,13571,1396408,149478882,16132176644,1743046774975,
%T A222921 188375987615301,20358991721595731,2200340247114860719,
%U A222921 237806554693426088256,25701465075957071507864,2777742291970854979335967
%N A222921 Number of nX3 0..4 arrays with no three equal values in a row horizontally or vertically, and new values 0..4 introduced in row major order.
%C A222921 Column 3 of A222924
%H A222921 R. H. Hardin, <a href="/A222921/b222921.txt">Table of n, a(n) for n = 1..210</a>
%F A222921 Empirical: a(n) = 110*a(n-1) +152*a(n-2) -39692*a(n-3) +79710*a(n-4) +796150*a(n-5) -1333952*a(n-6) -1226634*a(n-7) -23628904*a(n-8) +55965332*a(n-9) +65773086*a(n-10) -123947190*a(n-11) -86026499*a(n-12) +40387328*a(n-13) +128788688*a(n-14) -15240812*a(n-15) -94039632*a(n-16) +31862080*a(n-17) +28558744*a(n-18) -10861760*a(n-19) -2218496*a(n-20) -2531712*a(n-21) -1928192*a(n-22) +635904*a(n-23) +317952*a(n-24)
%e A222921 Some solutions for n=3
%e A222921 ..0..0..1....0..1..2....0..1..0....0..1..2....0..1..1....0..1..1....0..0..1
%e A222921 ..2..0..3....3..4..4....1..2..3....1..0..1....0..2..2....0..2..2....1..2..3
%e A222921 ..0..3..1....3..3..1....1..0..3....1..3..4....1..3..3....3..3..1....4..1..2
%K A222921 nonn
%O A222921 1,1
%A A222921 _R. H. Hardin_ Mar 09 2013