Number of n X n of nonnegative integers with all row and column sums equal to 4.
A172806
Number of n X n of nonnegative integers with all row and column sums equal to 4.
Terms
- a(0) =1a(1) =1a(2) =5a(3) =120a(4) =10147a(5) =2224955a(6) =1047649905a(7) =936670590450
External references
- oeis: A172806