Number of immersions of the oriented circle into the unoriented plane with n double points.

A008982

Number of immersions of the oriented circle into the unoriented plane with n double points.

Terms

    a(0) =1a(1) =2a(2) =5a(3) =21a(4) =102a(5) =640a(6) =4492a(7) =34047a(8) =272252a(9) =2268085a(10) =19502386a(11) =172113886a(12) =1551948268

External references