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A238249 Number of (n+1)X(2+1) 0..1 arrays with 2X2 subblock sums lexicographically nondecreasing columnwise and rowwise 1

%I #5 Feb 21 2014 05:29:02

%S 44,180,804,2818,9991,29995,90225,241945,649320,1605951,3974215,

%T 9269399,21628177,48322967,107991481,233776405,506133563,1070574873,

%U 2264593031,4710021487,9796211590,20129009598,41359935334,84255978136,171637137305

%N Number of (n+1)X(2+1) 0..1 arrays with 2X2 subblock sums lexicographically nondecreasing columnwise and rowwise

%C Column 2 of A238255

%H R. H. Hardin, <a href="/A238249/b238249.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 4*a(n-1) +16*a(n-2) -82*a(n-3) -99*a(n-4) +774*a(n-5) +196*a(n-6) -4456*a(n-7) +1106*a(n-8) +17464*a(n-9) -10080*a(n-10) -49212*a(n-11) +40922*a(n-12) +102532*a(n-13) -108728*a(n-14) -159592*a(n-15) +207747*a(n-16) +184428*a(n-17) -296048*a(n-18) -153442*a(n-19) +318857*a(n-20) +83878*a(n-21) -259308*a(n-22) -19872*a(n-23) +157052*a(n-24) -10232*a(n-25) -68768*a(n-26) +12128*a(n-27) +20592*a(n-28) -5472*a(n-29) -3776*a(n-30) +1280*a(n-31) +320*a(n-32) -128*a(n-33)

%e Some solutions for n=5

%e ..0..1..0....0..1..0....0..0..0....0..0..0....0..0..1....0..0..1....0..0..0

%e ..1..0..1....0..0..0....1..1..1....0..0..0....0..0..1....0..0..1....0..0..0

%e ..1..0..1....1..0..1....0..1..0....0..0..1....0..0..1....1..0..0....0..0..1

%e ..1..1..1....0..0..1....1..1..1....1..0..0....1..1..0....1..1..1....1..1..0

%e ..0..1..1....1..1..0....0..1..1....0..1..1....0..1..1....1..1..0....1..1..1

%e ..1..1..1....0..1..1....1..1..1....0..1..1....1..1..0....1..1..1....1..1..1

%K nonn

%O 1,1

%A _R. H. Hardin_, Feb 21 2014

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Last modified April 24 14:09 EDT 2024. Contains 371960 sequences. (Running on oeis4.)