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A253469 Number of (n+1) X (7+1) 0..2 arrays with every 2 X 2 subblock diagonal maximum minus antidiagonal minimum unequal to its neighbors horizontally, vertically, diagonally and antidiagonally. 1

%I

%S 7227096,44464,17000,15680,20000,20864,32000,41600,80000,124544,

%T 272000,456320,1040000,1783424,4112000,7091840,16400000,28325504,

%U 65552000,113260160,262160000,452998784,1048592000,1811953280,4194320000

%N Number of (n+1) X (7+1) 0..2 arrays with every 2 X 2 subblock diagonal maximum minus antidiagonal minimum unequal to its neighbors horizontally, vertically, diagonally and antidiagonally.

%H R. H. Hardin, <a href="/A253469/b253469.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 5*a(n-2) - 4*a(n-4) for n>6.

%F Empirical g.f.: 8*x*(903387 + 5558*x - 4514810*x^2 - 25830*x^3 + 3605423*x^4 + 15040*x^5) / ((1 - x)*(1 + x)*(1 - 2*x)*(1 + 2*x)). - _Colin Barker_, Dec 15 2018

%e Some solutions for n=1:

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

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

%Y Column 7 of A253468.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 01 2015

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Last modified January 19 01:11 EST 2021. Contains 340262 sequences. (Running on oeis4.)