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A203652 1/25 the number of (n+1)X5 0..4 arrays with every 2X2 subblock having equal diagonal elements or equal antidiagonal elements.

%I A203652 #7 Jul 22 2025 17:25:06
%S A203652 6561,519445,44577561,3906948333,343812029649,30292030417413,
%T A203652 2669260624372937,235230466316286557,20729666228601067777,
%U A203652 1826821038860074533877,160989718241260912957305
%N A203652 1/25 the number of (n+1)X5 0..4 arrays with every 2X2 subblock having equal diagonal elements or equal antidiagonal elements.
%C A203652 Column 4 of A203656
%H A203652 R. H. Hardin, <a href="/A203652/b203652.txt">Table of n, a(n) for n = 1..210</a>
%F A203652 Empirical: a(n) = 69*a(n-1) +2528*a(n-2) -75120*a(n-3) +59456*a(n-4) +1531904*a(n-5) -345088*a(n-6) -1646592*a(n-7)
%e A203652 Some solutions for n=4
%e A203652 ..0..2..2..0..0....4..1..0..1..1....0..3..2..3..4....1..2..4..4..4
%e A203652 ..4..0..2..2..0....0..4..1..3..1....4..0..3..3..3....4..1..2..4..2
%e A203652 ..3..4..0..2..2....0..0..4..1..3....2..4..0..3..1....1..3..1..2..0
%e A203652 ..0..3..4..0..2....2..0..0..4..1....3..2..4..0..3....3..3..3..1..2
%e A203652 ..3..0..3..4..0....3..2..0..0..4....4..3..2..4..0....2..3..1..3..1
%K A203652 nonn
%O A203652 1,1
%A A203652 _R. H. Hardin_ Jan 04 2012