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Number of (n+1)X2 0..3 arrays with every 2X2 subblock diagonal sum less antidiagonal sum equal to some horizontal or vertical neighbor 2X2 subblock diagonal sum less antidiagonal sum
1

%I #6 Mar 31 2012 12:36:02

%S 0,404,854,10296,37844,290174,1362488,8774626,45926642,275463688,

%T 1510531582,8783115912,49130660464,281836576008,1590115421874,

%U 9069855844118,51364113537584,292267799222808,1657869627853838

%N Number of (n+1)X2 0..3 arrays with every 2X2 subblock diagonal sum less antidiagonal sum equal to some horizontal or vertical neighbor 2X2 subblock diagonal sum less antidiagonal sum

%C Column 1 of A185640

%H R. H. Hardin, <a href="/A185637/b185637.txt">Table of n, a(n) for n = 1..200</a>

%F Empirical: a(n)=10*a(n-1)-11*a(n-2)-181*a(n-3)+913*a(n-4)-2534*a(n-5)+5804*a(n-6)-6040*a(n-7)-63917*a(n-8)+416786*a(n-9)-1628376*a(n-10)+4152240*a(n-11)-5982480*a(n-12)-534528*a(n-13)+38863872*a(n-14)-100047744*a(n-15)+170726400*a(n-16)-135198720*a(n-17)+75644928*a(n-18)

%e Some solutions for 3X2

%e ..1..2....3..0....3..2....0..2....1..2....3..1....3..3....2..1....2..0....2..2

%e ..2..3....2..1....2..1....1..1....0..0....2..1....3..3....0..0....2..1....0..0

%e ..2..3....2..3....2..1....2..0....2..1....1..1....0..0....2..3....1..1....1..1

%K nonn

%O 1,2

%A _R. H. Hardin_ Feb 01 2011