Number of n X n symmetric matrices with nonnegative integer entries with each row sum i equal to i (1..n).
A140722
Number of n X n symmetric matrices with nonnegative integer entries with each row sum i equal to i (1..n).
Terms
- a(0) =1a(1) =2a(2) =8a(3) =61a(4) =957a(5) =31520a(6) =2199080a(7) =328002710a(8) =105370907181
External references
- oeis: A140722