Number of n-node biconnected graphs with girth at least 5.

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =1a(5) =1a(6) =2a(7) =5a(8) =12a(9) =40a(10) =154a(11) =766a(12) =4672a(13) =34547a(14) =302185a(15) =3073267a(16) =35933851a(17) =479768761a(18) =7284446498a(19) =125435333136