Number of (2+2)-free naturally labeled posets on [n].
A367494
Number of (2+2)-free naturally labeled posets on [n].
Terms
- a(0) =1a(1) =1a(2) =2a(3) =7a(4) =37a(5) =272a(6) =2637a(7) =32469a(8) =493602a(9) =9062503a(10) =197409097a(11) =5027822588a(12) =147896295785
External references
- oeis: A367494