Number of isomorphism classes of simple quadrangulations of the sphere having n vertices and n-2 faces, with orientation-reversing isomorphisms forbidden.

A113202

Number of isomorphism classes of simple quadrangulations of the sphere having n vertices and n-2 faces, with orientation-reversing isomorphisms forbidden.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =3a(4) =10a(5) =21a(6) =83a(7) =298a(8) =1339a(9) =6049a(10) =29765a(11) =148842a(12) =770267a(13) =4054539a(14) =21743705a(15) =118237471a(16) =651370528a(17) =3628421181a(18) =20416662314a(19) =115919209155a(20) =663548898942

External references