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A222920 Number of nX2 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 A222920 #6 Jul 23 2025 03:15:53
%S A222920 2,15,174,3183,68076,1543538,35663142,829049736,19310392822,
%T A222920 450063924406,10491666753024,244592254688694,5702297247404918,
%U A222920 132941283209423448,3099351244544272614,72257348464516101894,1684586587434789765504
%N A222920 Number of nX2 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 A222920 Column 2 of A222924
%H A222920 R. H. Hardin, <a href="/A222920/b222920.txt">Table of n, a(n) for n = 1..210</a>
%F A222920 Empirical: a(n) = 28*a(n-1) -78*a(n-2) -789*a(n-3) +1250*a(n-4) +3796*a(n-5) -3288*a(n-6) -2208*a(n-7) +2432*a(n-8) -512*a(n-9) for n>11
%e A222920 Some solutions for n=3
%e A222920 ..0..1....0..1....0..1....0..0....0..1....0..1....0..0....0..0....0..1....0..0
%e A222920 ..0..0....1..0....0..2....1..0....2..2....2..0....1..2....1..2....2..3....1..1
%e A222920 ..1..0....0..1....3..3....2..1....0..0....3..4....1..3....0..3....0..1....1..1
%K A222920 nonn
%O A222920 1,1
%A A222920 _R. H. Hardin_ Mar 09 2013