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A235550 Number of (n+1)X(2+1) 0..1 arrays with the sum of each 2X2 subblock two extreme terms minus its two median terms lexicographically nondecreasing rowwise and columnwise 1

%I #4 Jan 12 2014 06:01:57

%S 46,202,814,2878,9320,27731,77606,205571,522118,1277701,3035682,

%T 7026779,15922886,35411253,77537074,167468443,357585774,755895685,

%U 1584418882,3296648763,6816697174,14019547045,28702737170,58535302827,118984571742

%N Number of (n+1)X(2+1) 0..1 arrays with the sum of each 2X2 subblock two extreme terms minus its two median terms lexicographically nondecreasing rowwise and columnwise

%C Column 2 of A235555

%H R. H. Hardin, <a href="/A235550/b235550.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 4*a(n-1) +9*a(n-2) -54*a(n-3) -15*a(n-4) +312*a(n-5) -133*a(n-6) -998*a(n-7) +840*a(n-8) +1896*a(n-9) -2268*a(n-10) -2088*a(n-11) +3472*a(n-12) +1088*a(n-13) -3120*a(n-14) +96*a(n-15) +1536*a(n-16) -384*a(n-17) -320*a(n-18) +128*a(n-19)

%e Some solutions for n=5

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

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 12 2014

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Last modified March 29 11:14 EDT 2024. Contains 371278 sequences. (Running on oeis4.)