Number of nonisomorphic unrooted unicursal planar maps with n edges and no vertices of valency 1 (unicursal means that exactly two vertices are of odd valency; there is an Eulerian path).

A069732

Number of nonisomorphic unrooted unicursal planar maps with n edges and no vertices of valency 1 (unicursal means that exactly two vertices are of odd valency; there is an Eulerian path).

Terms

    a(0) =0a(1) =0a(2) =2a(3) =7a(4) =40a(5) =239a(6) =1549a(7) =10396a(8) =71467a(9) =498598a(10) =3520015a(11) =25087426a(12) =180249182a(13) =1304148015a(14) =9494015372a(15) =69492950976a(16) =511147940104

External references