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 A252224 Number of (n+2) X (4+2) 0..2 arrays with every 3 X 3 subblock row and column sum 2 3 or 4 and every diagonal and antidiagonal sum not 2 3 or 4. 1

%I

%S 1442,7724,24932,58334,160688,512822,1619714,4972874,15236172,

%T 46914228,144610766,445412672,1371485862,4223410850,13006666602,

%U 40055759564,123355278788,379883410622,1169887334864,3602781631574,11095111201922

%N Number of (n+2) X (4+2) 0..2 arrays with every 3 X 3 subblock row and column sum 2 3 or 4 and every diagonal and antidiagonal sum not 2 3 or 4.

%H R. H. Hardin, <a href="/A252224/b252224.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 3*a(n-1) - a(n-2) + 3*a(n-3) + 3*a(n-4) - a(n-5) - a(n-6) for n>8.

%F Empirical g.f.: 2*x*(721 + 1699*x + 1601*x^2 - 6532*x^3 - 8440*x^4 - 3717*x^5 + 652*x^6 + 1072*x^7) / ((1 - x + 2*x^2 - x^3)*(1 - 2*x - 3*x^2 - x^3)). - _Colin Barker_, Dec 02 2018

%e Some solutions for n=4:

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

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

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

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

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

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

%Y Column 4 of A252228.

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 15 2014

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Last modified November 29 14:08 EST 2021. Contains 349416 sequences. (Running on oeis4.)