Number of (n+1) X (n+1) -11..11 symmetric matrices with every 2 X 2 subblock having sum zero.
A211719
Number of (n+1) X (n+1) -11..11 symmetric matrices with every 2 X 2 subblock having sum zero.
Terms
- a(0) =265a(1) =3059a(2) =35377a(3) =409883a(4) =4757545a(5) =55318979a(6) =644340577a(7) =7517728043a(8) =87854788825
External references
- oeis: A211719