Irregular triangular array read by rows: T(n,k) is the number of inequivalent n X n {0,1} matrices modulo permutation of the rows, containing exactly k 1's; n>=0, 0<=k<=n^2.
A220886
Irregular triangular array read by rows: T(n,k) is the number of inequivalent n X n {0,1} matrices modulo permutation of the rows, containing exactly k 1's; n>=0, 0<=k<=n^2.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =1a(4) =2a(5) =4a(6) =2a(7) =1a(8) =1a(9) =3a(10) =9a(11) =20a(12) =27a(13) =27a(14) =20a(15) =9a(16) =3a(17) =1a(18) =1a(19) =4a(20) =16a(21) =48a(22) =133a(23) =272a(24) =468a(25) =636a(26) =720a(27) =636a(28) =468a(29) =272
External references
- oeis: A220886