Number of immersions of oriented circle into oriented sphere with n double points.

A008986

Number of immersions of oriented circle into oriented sphere with n double points.

Terms

    a(0) =1a(1) =1a(2) =3a(3) =9a(4) =37a(5) =182a(6) =1143a(7) =7553a(8) =54559a(9) =412306a(10) =3251240a(11) =26478264a(12) =221714164a(13) =1900103364a(14) =16613990484a(15) =147816411921

External references