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A203376 Number of (n+1)X7 0..1 arrays with every 2X2 subblock having equal diagonal elements or equal antidiagonal elements.

%I A203376 #7 Jul 22 2025 17:11:24
%S A203376 2916,70996,1764360,44183028,1109832180,27913330472,702420750924,
%T A203376 17679917387404,445045123432096,11203277447970636,282028756620227124,
%U A203376 7099777698513424920,178729975670304808348,4499358353656818662428
%N A203376 Number of (n+1)X7 0..1 arrays with every 2X2 subblock having equal diagonal elements or equal antidiagonal elements.
%C A203376 Column 6 of A203378
%H A203376 R. H. Hardin, <a href="/A203376/b203376.txt">Table of n, a(n) for n = 1..210</a>
%F A203376 Empirical: a(n) = 55*a(n-1) -1109*a(n-2) +11330*a(n-3) -67206*a(n-4) +247404*a(n-5) -582440*a(n-6) +881876*a(n-7) -846764*a(n-8) +499200*a(n-9) -172400*a(n-10) +33152*a(n-11) -3264*a(n-12) +128*a(n-13)
%e A203376 Some solutions for n=4
%e A203376 ..0..1..1..0..1..1..0....0..1..1..1..1..1..1....1..1..1..0..1..1..0
%e A203376 ..0..0..1..1..0..1..1....1..0..1..1..0..1..1....1..1..0..1..1..0..0
%e A203376 ..1..0..0..1..1..1..0....1..1..1..1..1..0..1....1..1..1..1..0..0..1
%e A203376 ..0..0..1..0..1..1..1....0..1..0..1..0..1..0....0..1..1..0..0..1..1
%e A203376 ..1..0..0..0..0..1..0....1..0..0..0..1..0..1....1..0..1..1..0..0..1
%K A203376 nonn
%O A203376 1,1
%A A203376 _R. H. Hardin_ Dec 31 2011