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Number of n X 7 0..2 arrays with rows in nondecreasing lexicographic order and columns in nonincreasing lexicographic order.
1

%I #6 May 25 2024 23:52:27

%S 36,1254,69834,6275546,725674326,89730161098,10811999412826,

%T 1224101415304069,128795068372302728,12581278164317910030,

%U 1143931690129837256876,97156838914464540981998

%N Number of n X 7 0..2 arrays with rows in nondecreasing lexicographic order and columns in nonincreasing lexicographic order.

%C Column 7 of A278807.

%H R. H. Hardin, <a href="/A278806/b278806.txt">Table of n, a(n) for n = 1..20</a>

%e Some solutions for n=3

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

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

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

%Y Cf. A278807.

%K nonn

%O 1,1

%A _R. H. Hardin_, Nov 28 2016