Number of connected squarefree bipartite graphs on n vertices.

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =3a(5) =7a(6) =12a(7) =30a(8) =64a(9) =177a(10) =457a(11) =1403a(12) =4327a(13) =15024a(14) =54730a(15) =219311a(16) =942908a(17) =4426513a(18) =22525015a(19) =124896794a(20) =752933593a(21) =4938212176a(22) =35190683416a(23) =272266028155