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A253466 Number of (n+1) X (5+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 #10 Dec 14 2018 07:32:23

%S 162016,8536,5000,7496,8000,12680,20000,33416,68000,116360,260000,

%T 448136,1028000,1775240,4100000,7083656,16388000,28317320,65540000,

%U 113251976,262148000,452990600,1048580000,1811945096,4194308000,7247763080

%N Number of (n+1) X (5+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="/A253466/b253466.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*(20252 + 1067*x - 100635*x^2 - 4398*x^3 + 78883*x^4 + 1168*x^5) / ((1 - x)*(1 + x)*(1 - 2*x)*(1 + 2*x)). - _Colin Barker_, Dec 14 2018

%e Some solutions for n=4:

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

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

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

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

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

%Y Column 5 of A253468.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 01 2015

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Last modified February 22 15:19 EST 2024. Contains 370256 sequences. (Running on oeis4.)