Number of labeled interval orders on n elements: (2+2)-free posets.

A079144

Number of labeled interval orders on n elements: (2+2)-free posets.

Terms

    a(0) =1a(1) =1a(2) =3a(3) =19a(4) =207a(5) =3451a(6) =81663a(7) =2602699a(8) =107477247a(9) =5581680571a(10) =356046745023

External references