OFFSET
0,3
COMMENTS
Number of n X n symmetric matrices with nonnegative integer entries and all row and column sums 7. - Andrew Howroyd, Apr 07 2020
EXAMPLE
All solutions for 14X2
..1..1....1..1....1..1....1..1....1..1....1..1....1..0....1..1
..1..1....1..1....1..1....1..1....1..1....1..0....1..0....1..1
..1..0....1..1....1..1....1..1....1..1....1..0....1..0....1..1
..1..0....1..1....1..1....1..1....1..1....1..0....1..0....1..0
..1..0....1..0....1..1....1..1....1..1....1..0....1..0....1..0
..1..0....1..0....1..1....1..0....1..1....1..0....1..0....1..0
..1..0....1..0....1..0....1..0....1..1....1..0....1..0....1..0
..0..1....0..1....0..1....0..1....0..0....0..1....0..1....0..1
..0..1....0..1....0..0....0..1....0..0....0..1....0..1....0..1
..0..1....0..1....0..0....0..0....0..0....0..1....0..1....0..1
..0..1....0..0....0..0....0..0....0..0....0..1....0..1....0..1
..0..1....0..0....0..0....0..0....0..0....0..1....0..1....0..0
..0..0....0..0....0..0....0..0....0..0....0..1....0..1....0..0
..0..0....0..0....0..0....0..0....0..0....0..0....0..1....0..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 30 2011
EXTENSIONS
a(0)=1 prepended and terms a(9) and beyond from Andrew Howroyd, Apr 06 2020
STATUS
approved