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Number of (7*n) X n binary arrays with rows in nonincreasing order and 7 ones in every column.
1

%I #9 May 18 2020 03:01:12

%S 1,8,410,154279,335279744,3037611501499,85864898797026630,

%T 6108049486793195602061,940799711096710781211340486,

%U 282034644651263093966900548272466,152112222253533154849862379093617650250,138939503191252353429488898422015410111981523

%N Number of (7*n) X n binary arrays with rows in nonincreasing order and 7 ones in every column.

%e All solutions for 14 X 2:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

%Y Row 7 of A188392.

%K nonn

%O 1,2

%A _R. H. Hardin_, Mar 30 2011

%E a(7)-a(12) from _Andrew Howroyd_, May 17 2020