A188402 - OEIS

A188402

Number of (8*n) X 8 binary arrays with rows in nonincreasing order, n ones in every column and no more than 2 ones in any row.

%I #8 Apr 07 2020 14:53:41

%S 1,764,213798,22262244,1158207312,36218801244,767013376954,

%T 11930327925108,144413237202513,1419823497519000,11712930348839580,

%U 83160597646878696,518506187445244096,2885792129983693112,14530215365239964244,66929085400566337832,284683656715082259137

%N Number of (8*n) X 8 binary arrays with rows in nonincreasing order, n ones in every column and no more than 2 ones in any row.

%C Number of 8 X 8 symmetric matrices with nonnegative integer entries and all row and column sums n. - _Andrew Howroyd_, Apr 07 2020

%e Some solutions for 16X8

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

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

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

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

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

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

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

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

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

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

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

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

%Y Column 8 of A188403.

%K nonn

%O 0,2

%A _R. H. Hardin_, Mar 30 2011

%E a(0)=1 prepended and terms a(9) and beyond from _Andrew Howroyd_, Apr 07 2020