%I #10 Apr 07 2020 15:25:55
%S 1,1,6,69,1620,62781,3710272,313568636,36218801244,5518184697792,
%T 1078258692423672,264082675302603684,79537577428138854144,
%U 28988656113108616134732,12610397520409429024276176,6469939930732195901177163384,3874562148530193751600746715440,2683567291732998871830525552934800
%N Number of (5*n) X n binary arrays with rows in nonincreasing order, 5 ones in every column and no more than 2 ones in any row.
%C Number of n X n symmetric matrices with nonnegative integer entries and all row and column sums 5. - _Andrew Howroyd_, Apr 07 2020
%e All solutions for 10X2
%e ..1..1....1..1....1..1....1..1....1..0....1..1
%e ..1..1....1..0....1..1....1..1....1..0....1..1
%e ..1..1....1..0....1..1....1..0....1..0....1..1
%e ..1..1....1..0....1..1....1..0....1..0....1..0
%e ..1..0....1..0....1..1....1..0....1..0....1..0
%e ..0..1....0..1....0..0....0..1....0..1....0..1
%e ..0..0....0..1....0..0....0..1....0..1....0..1
%e ..0..0....0..1....0..0....0..1....0..1....0..0
%e ..0..0....0..1....0..0....0..0....0..1....0..0
%e ..0..0....0..0....0..0....0..0....0..1....0..0
%Y Row 5 of A188403.
%K nonn
%O 0,3
%A _R. H. Hardin_, Mar 30 2011
%E a(0)=1 prepended and terms a(10) and beyond from _Andrew Howroyd_, Apr 07 2020