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A203981 Number of (n+1) X 6 0..2 arrays with no 2 X 2 subblock having equal diagonal elements or equal antidiagonal elements, and new values 0..2 introduced in row major order.

%I A203981 #9 Jun 06 2018 05:41:11
%S A203981 1536,31104,629856,13071456,271918944,5671161216,118333620576,
%T A203981 2469841766784,51553851826176,1076137623724896,22463572543638624,
%U A203981 468912308350736736,9788249148960940416,204323642334833818464
%N A203981 Number of (n+1) X 6 0..2 arrays with no 2 X 2 subblock having equal diagonal elements or equal antidiagonal elements, and new values 0..2 introduced in row major order.
%C A203981 Column 5 of A203984.
%H A203981 R. H. Hardin, <a href="/A203981/b203981.txt">Table of n, a(n) for n = 1..210</a>
%F A203981 Empirical: a(n) = 25*a(n-1) - 45*a(n-2) - 963*a(n-3) + 2025*a(n-4) + 3645*a(n-5) - 6561*a(n-6).
%F A203981 Empirical g.f.: 96*x*(16 - 76*x - 819*x^2 + 2124*x^3 + 3321*x^4 - 6561*x^5) / ((1 - 25*x + 90*x^2 - 81*x^3)*(1 - 45*x^2 - 81*x^3)). - _Colin Barker_, Jun 06 2018
%e A203981 Some solutions for n=4:
%e A203981 ..0..0..0..0..0..0....0..0..0..1..0..0....0..0..0..0..0..0....0..0..0..1..2..2
%e A203981 ..1..1..1..1..2..2....1..1..2..2..2..2....1..1..2..2..1..1....1..1..2..1..0..0
%e A203981 ..2..2..2..0..0..1....2..0..0..1..1..1....2..0..0..0..0..2....0..0..2..1..2..2
%e A203981 ..1..1..1..1..2..1....1..1..2..2..0..0....2..1..2..2..1..2....2..1..2..0..0..0
%e A203981 ..0..2..2..0..0..1....0..0..0..1..1..1....0..0..0..0..0..2....2..0..2..1..1..1
%Y A203981 Cf. A203984.
%K A203981 nonn
%O A203981 1,1
%A A203981 _R. H. Hardin_, Jan 09 2012