Number of connected, unlabeled, unrooted 3-leaf power graphs on n vertices.

Terms

a(0) =1a(1) =1a(2) =2a(3) =5a(4) =12a(5) =32a(6) =82a(7) =227a(8) =629a(9) =1840a(10) =5456a(11) =16701a(12) =51939a(13) =164688a(14) =529070a(15) =1722271a(16) =5664786a(17) =18813360a(18) =62996841a(19) =212533216a(20) =721792751a(21) =2466135364a(22) =8471967927a(23) =29249059281a(24) =101440962284a(25) =353289339914