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A205409 Number of (n+2)X4 0..2 arrays with every 3X3 subblock having three equal elements in a row horizontally, vertically or nw-to-se diagonally exactly two ways, and new values 0..2 introduced in row major order.

%I A205409 #7 Jul 22 2025 18:50:27
%S A205409 3868,44596,549414,5686031,64878898,768581101,8606465750,98080551694,
%T A205409 1133347809296,12914400827409,147488385577992,1691863713691698,
%U A205409 19345357758536500,221200783159493283,2532531552219620474
%N A205409 Number of (n+2)X4 0..2 arrays with every 3X3 subblock having three equal elements in a row horizontally, vertically or nw-to-se diagonally exactly two ways, and new values 0..2 introduced in row major order.
%C A205409 Column 2 of A205415
%H A205409 R. H. Hardin, <a href="/A205409/b205409.txt">Table of n, a(n) for n = 1..210</a>
%e A205409 Some solutions for n=3
%e A205409 ..0..0..0..0....0..1..2..2....0..0..0..0....0..1..2..1....0..1..2..0
%e A205409 ..0..1..1..1....2..2..2..1....1..0..0..1....1..0..2..2....1..2..2..2
%e A205409 ..1..1..1..2....1..2..2..2....1..1..1..1....2..2..2..2....2..2..2..1
%e A205409 ..2..0..1..2....2..2..1..0....0..2..1..1....1..2..2..0....2..0..2..1
%e A205409 ..0..1..1..2....2..2..2..1....0..0..0..0....0..2..1..0....0..2..2..1
%K A205409 nonn
%O A205409 1,1
%A A205409 _R. H. Hardin_ Jan 26 2012