Number of abstract simplicial 2-complexes on {1,2,3,...,n+3} which triangulate the 2-sphere: C(n+3,2)*(4n+1)!/(3n+3)!.

A007816

Number of abstract simplicial 2-complexes on {1,2,3,...,n+3} which triangulate the 2-sphere: C(n+3,2)*(4n+1)!/(3n+3)!.

Terms

    a(0) =1a(1) =10a(2) =195a(3) =5712a(4) =223440a(5) =10929600a(6) =641277000a(7) =43859692800

External references