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Number of nX6 0..2 arrays with rows and columns lexicographically nondecreasing read forwards and nonincreasing read backwards
1

%I #5 Mar 31 2012 12:36:45

%S 3,48,2068,167625,14268351,795339012,27102769900,615440785548,

%T 10106227864338,127441635892627,1290114077123683,10846768837607450,

%U 77797729805055016,486398599750167133,2697872438447793007

%N Number of nX6 0..2 arrays with rows and columns lexicographically nondecreasing read forwards and nonincreasing read backwards

%C Column 6 of A201700

%H R. H. Hardin, <a href="/A201698/b201698.txt">Table of n, a(n) for n = 1..90</a>

%F Empirical: a(n) is a polynomial of degree 34

%e Some solutions for n=3

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Dec 03 2011