Triangle read by rows: T(n,m) is the number of inequivalent n X m matrices under action of the Klein group, with one-fifth of 1s, 2s, 3s, 4s and 5s (ordered occurrences rounded up/down if n*m != 0 mod 5).
A287021
Triangle read by rows: T(n,m) is the number of inequivalent n X m matrices under action of the Klein group, with one-fifth of 1s, 2s, 3s, 4s and 5s (ordered occurrences rounded up/down if n*m != 0 mod 5).
Terms
- a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =1a(6) =1a(7) =1a(8) =90a(9) =5712a(10) =1a(11) =1a(12) =1260a(13) =416064a(14) =168168000a(15) =1a(16) =60a(17) =28440a(18) =42045600a(19) =76385194200a(21) =1a(22) =180a(23) =415800a(24) =3216282300a(28) =1a(29) =630a(30) =8408400a(31) =320818773240
External references
- oeis: A287021