Number of 20 X 20 arrays of squares of integers, symmetric under 90-degree rotation, with all rows summing to n.
A156429
Number of 20 X 20 arrays of squares of integers, symmetric under 90-degree rotation, with all rows summing to n.
Terms
- a(0) =1a(1) =30240a(2) =569744280
External references
- oeis: A156429