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A253494 Number of (n+1) X (7+1) 0..2 arrays with every 2 X 2 subblock diagonal minus antidiagonal sum nondecreasing horizontally, vertically and ne-to-sw antidiagonally. 1

%I

%S 48293,51167,60586,82676,127898,220988,415106,827156,1722698,3728108,

%T 8381906,19618436,47878298,121758428,321599906,877526516,2458110698,

%U 7025471948,20378773106,59741111396,176432995898,523718388668

%N Number of (n+1) X (7+1) 0..2 arrays with every 2 X 2 subblock diagonal minus antidiagonal sum nondecreasing horizontally, vertically and ne-to-sw antidiagonally.

%H R. H. Hardin, <a href="/A253494/b253494.txt">Table of n, a(n) for n = 1..149</a>

%F Empirical: a(n) = 6*a(n-1) - 11*a(n-2) + 6*a(n-3) for n>6.

%F Empirical: a(n) = 49*3^(n-1) + 5322*2^(n-1) + 38777 for n>3.

%F Empirical g.f.: x*(48293 - 238591*x + 284807*x^2 - 7761*x^3 - 8714*x^4 - 480*x^5) / ((1 - x)*(1 - 2*x)*(1 - 3*x)). - _Colin Barker_, Dec 16 2018

%e Some solutions for n=4:

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

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

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

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

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

%Y Column 7 of A253495.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 02 2015

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Last modified June 28 07:25 EDT 2022. Contains 354903 sequences. (Running on oeis4.)