Number of disconnected regular simple graphs on n vertices with girth at least 5.

Terms

a(0) =0a(1) =0a(2) =1a(3) =1a(4) =2a(5) =1a(6) =2a(7) =1a(8) =2a(9) =1a(10) =3a(11) =2a(12) =4a(13) =3a(14) =5a(15) =5a(16) =7a(17) =7a(18) =10a(19) =10a(20) =15a(21) =15a(22) =21a(23) =21a(24) =39a(25) =30a(26) =104a(27) =42a(28) =649a(29) =58