Number of n X n matrices with nonnegative integer entries and every row and column sum <= 2.
A049088
Number of n X n matrices with nonnegative integer entries and every row and column sum <= 2.
Terms
- a(0) =1a(1) =3a(2) =26a(3) =451a(4) =12951a(5) =551681a(6) =32512618a(7) =2525962461a(8) =249675308081
External references
- oeis: A049088