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 A223579 Number of n X n 0..3 arrays with antidiagonals unimodal 1

%I

%S 4,256,204800,1331200000,51224576000000,9249109442560000000,

%T 6561595711835340800000000,15895655898196756312883200000000,

%U 117344147980184981008663340646400000000

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

%C Diagonal of A223585

%H R. H. Hardin, <a href="/A223579/b223579.txt">Table of n, a(n) for n = 1..48</a>

%F Let U(z) = (z^6+15*z^5+115*z^4+405*z^3+964*z^2+660*z+720)/720

%F a(n) = U(n) * product{ U(i)^2 , i=1..(n-1) }

%e Some solutions for n=3

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Mar 22 2013

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Last modified December 3 22:32 EST 2021. Contains 349468 sequences. (Running on oeis4.)