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%I #5 Mar 31 2012 12:36:58
%S 8503056,5292994896,3294791304336,2056114528873776,
%T 1283572086126147216,801390350388172407408,500356074758382054639504,
%U 312404527128988880482773744,195054597997333792597519483536
%N Number of (n+1)X7 0..3 arrays with no 2X2 subblock having equal diagonal elements or equal antidiagonal elements
%C Column 6 of A203826
%H R. H. Hardin, <a href="/A203824/b203824.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 678*a(n-1) -22734242*a(n-3) +910406337*a(n-4) +156697421244*a(n-5) -7894318906376*a(n-6) -298701635031072*a(n-7) +19095213955176408*a(n-8) -23161522711676608*a(n-9) -8870593536889707168*a(n-10) +74637360576235233504*a(n-11) +1149506147738408857488*a(n-12) -14956375338761404032576*a(n-13) +524896293102578305429248*a(n-15) -1594233946756949214802176*a(n-16)
%e Some solutions for n=4
%e ..1..1..1..1..2..1..2....3..2..3..2..0..2..3....2..3..2..1..0..2..1
%e ..3..0..2..3..0..1..3....0..1..0..1..3..2..0....0..3..0..3..3..2..1
%e ..1..0..1..3..0..1..2....3..2..3..1..3..2..1....0..2..0..2..0..2..1
%e ..2..0..2..2..0..3..2....3..0..3..0..3..0..1....3..2..3..2..3..2..0
%e ..2..1..3..1..0..1..0....1..1..1..0..1..2..2....1..0..3..0..3..1..3
%K nonn
%O 1,1
%A _R. H. Hardin_ Jan 06 2012
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