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Number of (n+2) X (2+2) 0..3 arrays with no increasing sequence of length 3 horizontally, vertically or antidiagonally downwards.
1

%I #6 May 31 2023 15:46:37

%S 7949773,1231134446,184701585960,27653665556487,4128363478149117,

%T 616170589022493877,91941352219976949775,13718603645716931922312,

%U 2046910445128969814115728,305412394098009944938215077

%N Number of (n+2) X (2+2) 0..3 arrays with no increasing sequence of length 3 horizontally, vertically or antidiagonally downwards.

%C Column 2 of A233801.

%H R. H. Hardin, <a href="/A233797/b233797.txt">Table of n, a(n) for n = 1..210</a>

%e Some solutions for n=1

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

%e ..0..0..0..1....1..0..0..0....0..2..2..0....0..2..2..3....1..3..1..1

%e ..1..1..3..1....0..0..0..3....1..0..0..3....1..0..2..1....1..0..0..0

%Y Cf. A233801.

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 16 2013