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A153370 Number of zig-zag paths from top to bottom of a rectangle of width 11 with n rows whose color is not that of the top right corner. 4

%I

%S 5,10,18,36,66,132,244,488,906,1812,3372,6744,12566,25132,46860,93720,

%T 174810,349620,652252,1304504,2433942,4867884,9083004,18166008,

%U 33897050,67794100,126503148,253006296,472111446,944222892,1761934444,3523868888

%N Number of zig-zag paths from top to bottom of a rectangle of width 11 with n rows whose color is not that of the top right corner.

%H Joseph Myers, <a href="http://www.polyomino.org.uk/publications/2008/bmo1-2009-q1.pdf">BMO 2008--2009 Round 1 Problem 1---Generalisation</a>

%F Empirical: G.f. -x*(2*x+1)*(3*x^4-12*x^2+5) / ( (2*x^2-1)*(x^4-4*x^2+1) ) and a(n)= +6*a(n-2) -9*a(n-4) +2*a(n-6). - _R. J. Mathar_, Jun 16 2011

%Y A153368, A153369, A153372. Bisections: A153371, A153373.

%K easy,nonn

%O 1,1

%A _Joseph Myers_, Dec 24 2008

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Last modified February 17 15:32 EST 2020. Contains 331998 sequences. (Running on oeis4.)