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Number of n X n 0..3 arrays with rows unimodal and antidiagonals nondecreasing.
1

%I #8 Jan 20 2024 13:37:56

%S 4,160,16060,2411246,451319098,96914926654,22835261226043,

%T 5750097317505437,1521786116504544601,418628292901694453231,

%U 118789461093773656747975,34580941641153629118242103

%N Number of n X n 0..3 arrays with rows unimodal and antidiagonals nondecreasing.

%C Diagonal of A224204.

%H R. H. Hardin, <a href="/A224198/b224198.txt">Table of n, a(n) for n = 1..17</a>

%e Some solutions for n=3

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

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

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

%Y Cf. A224204.

%K nonn

%O 1,1

%A _R. H. Hardin_, Apr 01 2013