Triangle read by rows: T(n,m) is the number of inequivalent n X m matrices under action of the Klein group, with one-third each of 1s, 2s and 3s (ordered occurrences rounded up/down if m*n != 0 mod 3).
A286892
Triangle read by rows: T(n,m) is the number of inequivalent n X m matrices under action of the Klein group, with one-third each of 1s, 2s and 3s (ordered occurrences rounded up/down if m*n != 0 mod 3).
Terms
- a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =3a(6) =1a(7) =3a(8) =27a(9) =438a(10) =1a(11) =6a(12) =140a(13) =8766a(14) =504504a(15) =1a(16) =16a(17) =1056a(18) =189774a(19) =33258880a(20) =6573403050a(21) =1a(22) =48a(23) =8730a(24) =4292514a(25) =2366403930a(28) =1a(29) =108a(30) =63108a(31) =99797220
External references
- oeis: A286892